275 research outputs found
Smart-antenna techniques for energy-efficient wireless sensor networks used in bridge structural health monitoring
Abstract: It is well known that wireless sensor networks differ from other computing platforms in that 1- they typically require a minimal amount of computing power at the nodes; 2- it is often desirable for sensor nodes to have drastically low power consumption. The main benefit of the this work is a substantial network life before batteries need to be replaced or, alternatively, the capacity to function off of modest environmental energy sources (energy harvesting). In the context of Structural Health Monitoring (SHM), battery replacement is particularly problematic since nodes can be in difficult to access locations. Furthermore, any intervention on a bridge may disrupt normal bridge operation, e.g. traffic may need to be halted. In this regard, switchbeam smart antennas in combination with wireless sensor networks (WSNs) have shown great potential in reducing implementation and maintenance costs of SHM systems. The main goal of implementing switch-beam smart antennas in our application is to reduce power consumption, by focusing the radiated energy only where it is needed. SHM systems capture the dynamic vibration information of a bridge structure in real-time in order to assess the health of the structure and to predict failures. Current SHM systems are based on piezoelectric patch sensors. In addition, the collection of data from the plurality of sensors distributed over the span of the bridge is typically performed through an expensive and bulky set of shielded wires which routes the information to a data sink at one end of the structure. The installation, maintenance and operational costs of such systems are extremely high due to high power consumption and the need for periodic maintenance. Wireless sensor networks represent an attractive alternative, in terms of cost, ease of maintenance, and power consumption. However, network lifetime in terms of node battery life must be very long (ideally 5–10 years) given the cost and hassle of manual intervention. In this context, the focus of this project is to reduce the global power consumption of the SHM system by implementing switched-beam smart antennas jointly with an optimized MAC layer. In the first part of the thesis, a sensor network platform for bridge SHM incorporating switched-beam antennas is modelled and simulated. where the main consideration is the joint optimization of beamforming parameters, MAC layer, and energy consumption. The simulation model, built within the Omnet++ network simulation framework, incorporates the energy consumption profiles of actual selected components (microcontroller, radio interface chip). The energy consumption and packet delivery ratio (PDR) of the network with switched-beam antennas is compared with an equivalent network based on omnidirectional antennas. In the second part of the thesis, this system model is leveraged to examine two distinct but interrelated aspects: Gallium Arsenide (GaAs) based solar energy harvesting and switched-beam antenna strategies. The main consideration here is the joint optimization of solar energy harvesting and switchedbeam directional antennas, where an equivalent network based on omnidirectional antennas acts as a baseline reference for comparison purposes.Il est bien connu que les réseaux de capteurs sans fils diffèrent des autres plateformes informatiques
étant donné 1- qu’ils requièrent typiquement une puissance de calcul minimale aux
noeuds du réseau ; 2- qu’il est souvent désirable que les noeuds capteurs aient une consommation
d’énergie dramatiquement faible. La principale retombée de ce travail réside en la durée
de vie allongée du réseau avant que les piles ne doivent être remplacées ou, alternativement,
la capacité de fonctionner indéfiniment à partir de modestes sources d’énergie ambiente (glânage
d’énergie). Dans le contexte du contrôle de la santé structurale (CSS), le remplacement de
piles est particulièrement problématique puisque les noeuds peuvent se trouver en des endroits
difficiles d’accès. De plus, toute intervention sur un pont implique une perturbation de l’opération
normale de la structure, par exemple un arrĂŞt du traffic. Dans ce contexte, les antennes
intelligentes à commutation de faisceau en combinaison avec les réseaux de capteurs sans fils
ont démontré un grand potentiel pour réduire les coûts de réalisation et d’entretien de systèmes
de CSS. L’objectif principal de l’intégration d’antennes à commutation de faisceau dans notre
application réside dans la réduction de la consommation énergétique, réalisée en concentrant
l’énergie radiée uniquement là où elle est nécessaire. Les systèmes de CSS capturent l’information
dynamique de vibration d’une structure de pont en temps réel de manière à évaluer la santé
de la structure et prédire les failles. Les systèmes courants de CSS sont basés sur des senseurs
piézoélectriques planaires. De plus, la collecte de données à partir de la pluralité de senseurs
distribués sur l’étendue du pont est typiquement effectuée par le biais d’un ensemble coûteux
et encombrant de câbles blindés qui véhiculent l’information jusqu’à un point de collecte à une
extremité de la structure. L’installation, l’entretien, et les coûts opérationnels de tels systèmes
sont extrêmement élevés étant donné la consommation de puissance élevée et le besoin d’entretien
régulier. Les réseaux de capteurs sans fils représentent une alternative attrayante, en termes
de coût, facilité d’entretien et consommation énergétique. Toutefois, la vie de réseau en termes
de la durée de vie des piles doit être très longue (idéalement de 5 à 10 ans) étant donné le coût
et les problèmes liés à l’intervention manuelle. Dans ce contexte, ce projet se concentre sur la
réduction de la consommation de puissance globale d’un système de CSS en y intégrant des
antennes intelligentes à commutation de faisceau conjointement avec une couche d’accès au
médium (couche MAC) optimisée. Dans la première partie de la thèse, une plateforme de réseau
de capteurs sans fils pour le CSS d’un pont incorporant des antennes à commutation de faisceaux
est modélisé et simulé, avec pour considération principale l’optimisation des paramètres
de sélection de faisceau, de la couche MAC et de la consommation d’énergie. Le modèle de
simulation, construit dans le logiciel de simulation de réseaux Omnet++, incorpore les profils
de consommation d’énergie de composants réels sélectionnés (microcontrôleur, puce d’interface
radio). La consommation d’énergie et le taux de livraison de paquets du réseau avec antennes
à commutation de faisceau est comparé avec un réseau équivalent basé sur des antennes omnidirectionnelles.
Dans la deuxième partie de la thèse, le modèle système proposĂ© est mis Ă
contribution pour examiner deux aspects distrincts mais interreliés : le glânage d’énergie à partir
de cellules solaire à base d’arséniure de Gallium (GaAs) et les stratégies liées aux antennes
à commutation de faisceau. La considération principale ici est l’optimisation conjointe du glânage d’énergie et des antennes à commutation de faisceau, en ayant pour base de comparaison
un réseau équivalent à base d’antennes omnidirectionnelles
Optimization of Spectrum Management in Massive Array Antenna Systems with MIMO
Fifth generation (5G), is being considered as a revolutionary technology in the telecommunication
domain whose the challenges are mainly to achieve signal quality and great ability to
work with free spectrum in the millimetre waves. Besides, other important innovations are the
introduction of a more current architecture and the use of multiple antennas in transmission
and reception. Digital communication using multiple input and multiple output (MIMO) wireless
links has recently emerged as one of the most significant technical advances in modern communications.
MIMO technology is able to offer a large increase in the capacity of these systems,
without requiring a considerable increase in bandwidth or power required for transmission.
This dissertation presents an overview of theoretical concepts of MIMO systems. With such a
system a spatial diversity gain can be obtained by using space-time codes, which simultaneously
exploit the spatial domain and the time domain. SISO, SIMO and MISO systems are differentiated
by their channel capacity and their configuration in relation to the number of antennas in the
transmitter/receiver. To verify the effectiveness of the MIMO systems a comparison between the
capacity of SISO and MIMO systems has been performed using the Shannon’s principles. In the
MIMO system some variations in the number of antennas arrays have been considered, and the
superiority of transmission gains of the MIMO systems have been demonstrated. Combined with
millimetre waves (mmWaves) technology, massive MIMO systems, where the number of antennas
in the base station and the number of users are large, is a promising solution.
SDR implementations have been performed considering a platform with Matlab code applied to
MIMO 2x2 Radio and Universal Software Peripheral Radio (USRP). A detailed study was initially
conducted to analyze the architecture of the USRP. Complex structures of MIMO systems can
be simplified by using mathematical methods implemented in Matlab for the synchronization of
the USRP in the receiver side. SISO transmission and reception techniques have been considered
to refine the synchronization (with 16-QAM), thus facilitating the future implementation of the
MIMO system. OpenAirInterface has been considered for 4G and 5G implementations of actual
mobile radio communication systems. Together with the practical MIMO, this type of solution is
the starting point for future hardware building blocks involving massive MIMO systems.A quinta geração (5G) está sendo considerada uma tecnologia revolucionária no setor de telecomunicações,
cujos desafios são principalmente a obtenção de qualidade de sinal e grande capacidade
de trabalhar com espectro livre nas ondas milimétricas. Além disso, outras inovações
importantes são a introdução de uma arquitetura mais atual e o uso de múltiplas antenas em
transmissão e recepção. A comunicação digital usando ligaçõe sem fio de múltiplas entradas e
mĂşltiplas saĂdas (MIMO) emergiu recentemente como um dos avanços tĂ©cnicos mais significativos
nas comunicações modernas. A tecnologia MIMO é capaz de oferecer um elevado aumento na
capacidade, sem exigir um aumento considerável na largura de banda ou potência transmitida.
Esta dissertação apresenta uma visão geral dos conceitos teóricos dos sistemas MIMO. Com esses
sistemas, um ganho de diversidade espacial pode ser obtido utilizando códigos espaço-tempo
reais. Os sistemas SISO, SIMO e MISO sĂŁo diferenciados pela capacidade de seus canais e a sua
configuração em relação ao número de antenas no emissor/receptor. Para verificar a eficiência
dos sistemas MIMO, realizou-se uma comparação entre a capacidade dos sistemas SISO e MIMO
utilizado os princĂpios de Shannon. Nos sistemas MIMO condecideraram-se algumas variações no
nĂşmero de agregados de antenas, e a superioridade dos ganhos de transmissĂŁo dos sistemas MIMO
foi demonstrada. Combinado com a tecnologia de ondas milimétricas (mmWaves), os sistemas
massivos MIMO, onde o número de antenas na estação base e o número de usuários são grandes,
são uma solução promissora.
As implementações do SDR foram realizadas considerando uma plataforma com código Matlab
aplicado aos rádios MIMO 2x2 e Universal Software Peripheral Radio (USRP). Um estudo detalhado
foi inicialmente conduzido para analisar a arquitetura da USRP. Estruturas complexas de sistemas
MIMO podem ser simplificadas usando métodos matemáticos implementados no Matlab para a
sincronização do USRP no lado do receptor. Consideraram-se técnicas de transmissão e recepção
SISO para refinar a sincronização (com 16-QAM), facilitando assim a implementação futura do
sistema MIMO . Considerou-se o OpenAirInterface para implementações 4G e 5G de sistemas
reais de comunicações móveis. Juntamente com o MIMO na pratica, este tipo de solução é
o ponto de partida para futuros blocos de construção de hardware envolvendo sistemas MIMO
massivos
Advanced Modulation and Coding Technology Conference
The objectives, approach, and status of all current LeRC-sponsored industry contracts and university grants are presented. The following topics are covered: (1) the LeRC Space Communications Program, and Advanced Modulation and Coding Projects; (2) the status of four contracts for development of proof-of-concept modems; (3) modulation and coding work done under three university grants, two small business innovation research contracts, and two demonstration model hardware development contracts; and (4) technology needs and opportunities for future missions
A Survey on Data Plane Programming with P4: Fundamentals, Advances, and Applied Research
With traditional networking, users can configure control plane protocols to
match the specific network configuration, but without the ability to
fundamentally change the underlying algorithms. With SDN, the users may provide
their own control plane, that can control network devices through their data
plane APIs. Programmable data planes allow users to define their own data plane
algorithms for network devices including appropriate data plane APIs which may
be leveraged by user-defined SDN control. Thus, programmable data planes and
SDN offer great flexibility for network customization, be it for specialized,
commercial appliances, e.g., in 5G or data center networks, or for rapid
prototyping in industrial and academic research. Programming
protocol-independent packet processors (P4) has emerged as the currently most
widespread abstraction, programming language, and concept for data plane
programming. It is developed and standardized by an open community and it is
supported by various software and hardware platforms. In this paper, we survey
the literature from 2015 to 2020 on data plane programming with P4. Our survey
covers 497 references of which 367 are scientific publications. We organize our
work into two parts. In the first part, we give an overview of data plane
programming models, the programming language, architectures, compilers,
targets, and data plane APIs. We also consider research efforts to advance P4
technology. In the second part, we analyze a large body of literature
considering P4-based applied research. We categorize 241 research papers into
different application domains, summarize their contributions, and extract
prototypes, target platforms, and source code availability.Comment: Submitted to IEEE Communications Surveys and Tutorials (COMS) on
2021-01-2
Dirty RF Signal Processing for Mitigation of Receiver Front-end Non-linearity
Moderne drahtlose Kommunikationssysteme stellen hohe und teilweise
gegensätzliche Anforderungen an die Hardware der Funkmodule, wie z.B.
niedriger Energieverbrauch, große Bandbreite und hohe Linearität. Die
Gewährleistung einer ausreichenden Linearität ist, neben anderen analogen
Parametern, eine Herausforderung im praktischen Design der Funkmodule. Der
Fokus der Dissertation liegt auf breitbandigen HF-Frontends fĂĽr
Software-konfigurierbare Funkmodule, die seit einigen Jahren kommerziell
verfĂĽgbar sind. Die praktischen Herausforderungen und Grenzen solcher
flexiblen Funkmodule offenbaren sich vor allem im realen Experiment. Eines
der Hauptprobleme ist die Sicherstellung einer ausreichenden analogen
Performanz ĂĽber einen weiten Frequenzbereich. Aus einer Vielzahl an
analogen Störeffekten behandelt die Arbeit die Analyse und Minderung von
Nichtlinearitäten in Empfängern mit direkt-umsetzender Architektur. Im
Vordergrund stehen dabei Signalverarbeitungsstrategien zur Minderung
nichtlinear verursachter Interferenz - ein Algorithmus, der besser unter
"Dirty RF"-Techniken bekannt ist. Ein digitales Verfahren nach der
Vorwärtskopplung wird durch intensive Simulationen, Messungen und
Implementierung in realer Hardware verifiziert. Um die LĂĽcken zwischen
Theorie und praktischer Anwendbarkeit zu schlieĂźen und das Verfahren in
reale Funkmodule zu integrieren, werden verschiedene Untersuchungen
durchgefĂĽhrt. Hierzu wird ein erweitertes Verhaltensmodell entwickelt, das
die Struktur direkt-umsetzender Empfänger am besten nachbildet und damit
alle Verzerrungen im HF- und Basisband erfasst. DarĂĽber hinaus wird die
Leistungsfähigkeit des Algorithmus unter realen Funkkanal-Bedingungen
untersucht. Zusätzlich folgt die Vorstellung einer ressourceneffizienten
Echtzeit-Implementierung des Verfahrens auf einem FPGA. AbschlieĂźend
diskutiert die Arbeit verschiedene Anwendungsfelder, darunter spektrales
Sensing, robuster GSM-Empfang und GSM-basiertes Passivradar. Es wird
gezeigt, dass nichtlineare Verzerrungen erfolgreich in der digitalen
Domäne gemindert werden können, wodurch die Bitfehlerrate gestörter
modulierter Signale sinkt und der Anteil nichtlinear verursachter
Interferenz minimiert wird. SchlieĂźlich kann durch das Verfahren die
effektive Linearität des HF-Frontends stark erhöht werden. Damit wird der
zuverlässige Betrieb eines einfachen Funkmoduls unter dem Einfluss der
Empfängernichtlinearität möglich. Aufgrund des flexiblen Designs ist der
Algorithmus für breitbandige Empfänger universal einsetzbar und ist nicht
auf Software-konfigurierbare Funkmodule beschränkt.Today's wireless communication systems place high requirements on the
radio's hardware that are largely mutually exclusive, such as low power
consumption, wide bandwidth, and high linearity. Achieving a sufficient
linearity, among other analogue characteristics, is a challenging issue in
practical transceiver design. The focus of this thesis is on wideband
receiver RF front-ends for software defined radio technology, which became
commercially available in the recent years. Practical challenges and
limitations are being revealed in real-world experiments with these radios.
One of the main problems is to ensure a sufficient RF performance of the
front-end over a wide bandwidth. The thesis covers the analysis and
mitigation of receiver non-linearity of typical direct-conversion receiver
architectures, among other RF impairments. The main focus is on DSP-based
algorithms for mitigating non-linearly induced interference, an approach
also known as "Dirty RF" signal processing techniques. The conceived
digital feedforward mitigation algorithm is verified through extensive
simulations, RF measurements, and implementation in real hardware. Various
studies are carried out that bridge the gap between theory and practical
applicability of this approach, especially with the aim of integrating that
technique into real devices. To this end, an advanced baseband behavioural
model is developed that matches to direct-conversion receiver architectures
as close as possible, and thus considers all generated distortions at RF
and baseband. In addition, the algorithm's performance is verified under
challenging fading conditions. Moreover, the thesis presents a
resource-efficient real-time implementation of the proposed solution on an
FPGA. Finally, different use cases are covered in the thesis that includes
spectrum monitoring or sensing, GSM downlink reception, and GSM-based
passive radar. It is shown that non-linear distortions can be successfully
mitigated at system level in the digital domain, thereby decreasing the bit
error rate of distorted modulated signals and reducing the amount of
non-linearly induced interference. Finally, the effective linearity of the
front-end is increased substantially. Thus, the proper operation of a
low-cost radio under presence of receiver non-linearity is possible. Due to
the flexible design, the algorithm is generally applicable for wideband
receivers and is not restricted to software defined radios
On-Chip Integrated Functional Near Infra-Red Spectroscopy (fNIRS) Photoreceiver for Portable Brain Imaging
RÉSUMÉ
L'imagerie cérébrale fonctionnelle utilisant la Spectroscopie Fonctionnelle Proche-Infrarouge (SFPI)
propose un outil portatif et non invasif de surveillance de l'oxygénation du sang. SFPI est une technique de
haute rĂ©solution temporelle non invasive, sĂ»r, peu intrusive en temps rĂ©el et pour l'imagerie cĂ©rĂ©brale Ă
long terme. Il permet de détecter des signaux hémodynamiques à la fois rapides et neuronaux ou lents. Outre les avantages importants des systèmes SFPI, ils souffrent encore de quelques inconvénients,
notamment d’une faible résolution spatiale, d’un bruit de niveau modérément élevé et d’une grande
sensibilité au mouvement. Afin de surmonter les limites des systèmes actuellement disponibles de SFPI non-portables, dans cette thèse, nous en avons introduit une nouvelle de faible puissance, miniaturisée sur une puce photodétecteur frontal destinée à des systèmes de SFPI portables. Elle contient du silicium
photodiode à avalanche (SiAPD), un amplificateur de transimpédance (TIA), et « Quench-Reset », circuits
mis en oeuvre en utilisant les technologies CMOS standards pour fonctionner dans les deux modes :
linéaire et Geiger. Ainsi, elle peut être appliquée pour les deux fNIRS : en onde continue (CW- SFPI) et
pour des applications de comptage de photon unique. Plusieurs SiAPDs ont été mises en oeuvre dans de nouvelles structures et formes (rectangulaires, octogonales, double APDs, imbriquées, netted, quadratiques et hexadecagonal) en utilisant différentes techniques de prévention de la dégradation de bord
prématurée. Les principales caractéristiques des SiAPDs sont validées et l'impact de chaque paramètre ainsi que les simulateurs de l'appareil (TCAD, COMSOL, etc) ont été étudiés sur la base de la simulation et de mesure des résultats. Proposées SiAPDs techniques d'exposition avec un gain de grande avalanche,
tension faible ventilation et une grande efficacité de détection des photons dans plus de faibles taux de comptage sombres. Trois nouveaux produits à haut gain, bande passante (GBW) et à faible bruit TIA sont introduits basés sur le concept de gain distribué, d’amplificateur logarithmique et sur le rejet automatique
du bruit pour être appliqué en mode de fonctionnement linéaire. Le TIA proposé offre une faible consommation, un gain de haute transimpédance, une bande passante ajustable et un très faible bruit
d'entrée et de sortie. Le nouveau circuit mixte trempe-reset (MQC) et un MQC contrôlable (CMQC)
frontaux offrent une faible puissance, une haute vitesse de comptage de photons avec un commandable de
temps de hold-off et temps de réinitialiser. La première intégration sur puce de SiAPDs avec TIA et Photon circuit de comptage a été démontrée et montre une amélioration de l'efficacité de la
photodétection, spécialement en ce qui concerne la sensibilité, la consommation d'énergie et le rapport signal sur bruit.----------ABSTRACT
Optical brain imaging using functional near infra-red spectroscopy (fNIRS) offers a direct and
noninvasive tool for monitoring of blood oxygenation. fNIRS is a noninvasive, safe, minimally
intrusive, and high temporal-resolution technique for real-time and long-term brain imaging. It allows detecting both fast-neuronal and slow-hemodynamic signals. Besides the significant
advantages of fNIRS systems, they still suffer from few drawbacks including low spatial-
resolution, moderately high-level noise and high-sensitivity to movement. In order to overcome
the limitations of currently available non-portable fNIRS systems, we have introduced a new
low-power, miniaturized on-chip photodetector front-end intended for portable fNIRS systems. It
includes silicon avalanche photodiode (SiAPD), Transimpedance amplifier (TIA), and Quench-
Reset circuitry implemented using standard CMOS technologies to operate in both linear and
Geiger modes. So it can be applied for both continuous-wave fNIRS (CW-fNIRS) and also
single-photon counting applications. Several SiAPDs have been implemented in novel structures
and shapes (Rectangular, Octagonal, Dual, Nested, Netted, Quadratic and Hexadecagonal) using
different premature edge breakdown prevention techniques. The main characteristics of the
SiAPDs are validated and the impact of each parameter and the device simulators (TCAD,
COMSOL, etc.) have been studied based on the simulation and measurement results. Proposed
techniques exhibit SiAPDs with high avalanche-gain (up to 119), low breakdown-voltage (around
12V) and high photon-detection efficiency (up to 72% in NIR region) in additional to a low dark-
count rate (down to 30Hz at 1V excess bias voltage). Three new high gain-bandwidth product
(GBW) and low-noise TIAs are introduced and implemented based on distributed-gain concept,
logarithmic-amplification and automatic noise-rejection and have been applied in linear-mode of operation. The implemented TIAs offer a power-consumption around 0.4 mW, transimpedance gain of 169 dBΩ, and input-output current/voltage noises in fA/pV range accompanied with ability to tune the gain, bandwidth and power-consumption in a wide range. The implemented
mixed quench-reset circuit (MQC) and controllable MQC (CMQC) front-ends offer a quenchtime of 10ns, a maximum power-consumption of 0.4 mW, with a controllable hold-off and resettimes. The on-chip integration of SiAPDs with TIA and photon-counting circuitries has been demonstrated showing improvement of the photodetection-efficiency, specially regarding to the
sensitivity, power-consumption and signal-to-noise ratio (SNR) characteristics
16th Annual Symposium of the School of Science, Engineering and Health
In this 16th Annual Symposium of the School of Science, Engineering, and Health, our faculty, staff and students continue the strong tradition of showcasing student and faculty innovation, creativity, and productivity in our academic departments. Basic and applied research in science and health fields stem from curiosity, acquired skill, and a desire to test and improve processes from foundational principles. The outcomes of scientific research expand intellectual understanding and have tremendous impact on quality of life, environmental health, and human flourishing.
Angela C. Hare, Ph.D.
Dean of the School of Science, Engineering and Healt
Recommended from our members
Hardware-Software Integrated Silicon Photonic Systems
Fabrication of integrated photonic devices and circuits in a CMOS-compatible process or foundry is the essence of the silicon photonic platform. Optical devices in this platform are enabled by the high index contrast between silicon and silicon on insulator. These devices offer potential benefits when integrated with existing and emerging high performance microelectronics. Integration of silicon photonics with small footprints and power-efficient and high-bandwidth operation has long been cited as a solution to existing issues in high performance interconnects for telecommunications and data communication. Stemming from this historic application in communications, new applications in sensing arrays, biochemistry, and even entertainment continue to grow. However, for many technologies to successfully adopt silicon photonics and reap the perceived benefits, the silicon photonic platform must extend toward development of a full ecosystem. Such extension includes implementation of low cost and robust electronic-photonic packaging techniques for all applications. In an ecosystem implemented with services ranging from device fabrication all the way to packaged products, ease-of-use and ease-of-deployment in systems that require many hardware and software components becomes possible.
With the onset of the Internet of Things (IoT), nearly all technologies—sensors, compute, communication devices, etc.—persist in systems with some level of localized or distributed software interaction. These interactions often require a level of networked communications. For silicon photonics to penetrate technologies comprising IoT, it is advantageous to implement such devices in a hardware-software integrated way. Meaning, all functionalities and interactions related to the silicon photonic devices are well defined in terms of the physicality of the hardware. This hardware is then abstracted into various levels of software as needed in the system. The power of hardware-software integration allows many of the piece-wise demonstrated functionalities of silicon photonics to easily translate to commercial implementation.
This work begins by briefly highlighting the challenges and solutions for transforming existing silicon photonic platforms to a full-fledged silicon photonic ecosystem. The highlighted solutions in development consist of tools for fabrication, testing, subsystem packaging, and system validation. Building off the knowledge of a silicon photonic ecosystem in development, this work continues by demonstrating various levels of hardware-software integration. These are primarily focused on silicon photonic interconnects.
The first hardware-software integration-focused portion of this work explores silicon microring-based devices as a key building block for greater silicon photonic subsystems. The microring’s sensitivity to thermal fluctuations is identified not as a flaw, but as a tool for functionalization. A logical control system is implemented to mitigate thermal effects that would normally render a microring resonator inoperable. The mechanism to control the microring is extended and abstracted with software programmability to offer wavelength routing as a network primitive. This functionality, available through hardware-software integration, offers the possibility for ubiquitous deployment of such microring devices in future photonic interconnection networks.
The second hardware-software integration-focused portion of this work explores dynamic silicon photonic switching devices and circuits. Specifically, interactions with and implications of high-speed data propagation and link layer control are demonstrated. The characteristics of photonic link setup include transients due to physical layer optical effects, latencies involved with initializing burst mode links, and optical link quality. The impacts on the functionalities and performance offered by photonic devices are explored. An optical network interface platform is devised using FPGAs to encapsulate hardware and software for controlling these characteristics using custom hardware description language, firmware, and software. A basic version of a silicon photonic network controller using FPGAs is used as a tool to demonstrate a highly scalable switch architecture using microring resonators. This architecture would not be possible without some semblance of this controller, combined with advanced electronic-photonic packaging. A more advanced deployment of the network interface platform is used to demonstrate a method for accelerating photonic links using out-of-band arbitration. A first demonstration of this platform is performed on a silicon photonic microring router network. A second demonstration is used to further explore the feasibility of full hardware-software integrated photonic device actuation, link layer control, and out-of-band arbitration. The demonstration is performed on a complete silicon photonic network with both spatial switching and wavelength routing functionalities.
The aforementioned hardware-software integration mechanisms are rigorously tested for data communications applications. Capabilities are shown for very reliable, low latency, and dynamic high-speed data delivery using silicon photonic devices. Applying these mechanisms to complete electronic-photonic packaged subsystems provides a strong path to commercial manifestations of functional silicon photonic devices
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