Next Generation of Energy Residential Gateways for Demand Response and Dynamic Pricing

Predictions about electric energy needs, based on current electric energy models, forecast that the global energy consumption on Earth for 2050 will double present rates. Using distributed procedures for control and integration, the expected needs can be halved. Therefore implementation of Smart Grids is necessary. Interaction between final consumers and utilities is a key factor of future Smart Grids. This interaction is aimed to reach efficient and responsible energy consumption. Energy Residential Gateways (ERG) are new in-building devices that will govern the communication between user and utility and will control electric loads. Utilities will offer new services empowering residential customers to lower their electric bill. Some of these services are Smart Metering, Demand Response and Dynamic Pricing. This paper presents a practical development of an ERG for residential buildings.

Building Trust for Lambda-Congenial Secret Groups

Establishing trust while preserving privacy is a challenging research problem. In this paper we introduce lambda -congenial secret groups which allow users to recognize trusted partners based on common attributes while preserving their anonymity and privacy. Such protocols are different from authentication protocols, since the latter are based on identities, while the former are based on attributes. Introducing attributes in trust establishment allows a greater flexibility but also brings up several issues. In this paper, we investigate the problem of building trust with attributes by presenting motivating examples, analyzing the security requirements and giving an informal definition. We also survey one of the most related techniques, namely private matching, and finally present solutions based on it.

Formal verification of safety protocol in train control system

In order to satisfy the safety-critical requirements, the train control system (TCS) often employs a layered safety communication protocol to provide reliable services. However, both description and verification of the safety protocols may be formidable due to the system complexity. In this paper, interface automata (IA) are used to describe the safety service interface behaviors of safety communication protocol. A formal verification method is proposed to describe the safety communication protocols using IA and translate IA model into PROMELA model so that the protocols can be verified by the model checker SPIN. A case study of using this method to describe and verify a safety communication protocol is included. The verification results illustrate that the proposed method is effective to describe the safety protocols and verify deadlocks, livelocks and several mandatory consistency properties. A prototype of safety protocols is also developed based on the presented formally verifying method.

ICTD Work, Plus mFeel : improving communication in resource-poor settings

This issue's Works-In-Progress department has four entries related to the issue's theme, Information and Communication Technologies for Development (ICTD). They are ���Sustainable ICT in Agricultural Value Chains���, ���Measuring Social Inclusion in Primary Schools���, ���An Architecture for Green Mobile Computation���, and ���Improving Communication in Resource-Poor Settings���. A fifth entry, ���mFeel: An Affective Mobile System���, covers the mFeel mobile system, which combines context awareness with affective and cognitive techniques.

Model-Driven Methodology for Rapid Deployment of Smart Spaces based on Resource-Oriented Architectures

Advances in electronics nowadays facilitate the design of smart spaces based on physical mash-ups of sensor and actuator devices. At the same time, software paradigms such as Internet of Things (IoT) and Web of Things (WoT) are motivating the creation of technology to support the development and deployment of web-enabled embedded sensor and actuator devices with two major objectives: (i) to integrate sensing and actuating functionalities into everyday objects, and (ii) to easily allow a diversity of devices to plug into the Internet. Currently, developers who are applying this Internet-oriented approach need to have solid understanding about specific platforms and web technologies. In order to alleviate this development process, this research proposes a Resource-Oriented and Ontology-Driven Development (ROOD) methodology based on the Model Driven Architecture (MDA). This methodology aims at enabling the development of smart spaces through a set of modeling tools and semantic technologies that support the definition of the smart space and the automatic generation of code at hardware level. ROOD feasibility is demonstrated by building an adaptive health monitoring service for a Smart Gym.

Using online presence to improve online collaborative learning

Social software tools have become an integral part of students? personal lives and their primary communication medium. Likewise, these tools are increasingly entering the enterprise world (within the recent trend known as Enterprise 2.0) and becoming a part of everyday work routines. Aiming to keep the pace with the job requirements and also to position learning as an integral part of students? life, the field of education is challenged to embrace social software. Personal Learning Environments (PLEs) emerged as a concept that makes use of social software to facilitate collaboration, knowledge sharing, group formation around common interests, active participation and reflective thinking in online learning settings. Furthermore, social software allows for establishing and maintaining one?s presence in the online world. By being aware of a student's online presence, a PLE is better able to personalize the learning settings, e.g., through recommendation of content to use or people to collaborate with. Aiming to explore the potentials of online presence for the provision of recommendations in PLEs, in the scope of the OP4L project, we have develop a software solution that is based on a synergy of Semantic Web technologies, online presence and socially-oriented learning theories. In this paper we present the current results of this research work.

Ubiquitous green computing techniques for high demand applications in smart environments

Ubiquitous sensor network deployments, such as the ones found in Smart cities and Ambient intelligence applications, require constantly increasing high computational demands in order to process data and offer services to users. The nature of these applications imply the usage of data centers. Research has paid much attention to the energy consumption of the sensor nodes in WSNs infrastructures. However, supercomputing facilities are the ones presenting a higher economic and environmental impact due to their very high power consumption. The latter problem, however, has been disregarded in the field of smart environment services. This paper proposes an energy-minimization workload assignment technique, based on heterogeneity and application-awareness, that redistributes low-demand computational tasks from high-performance facilities to idle nodes with low and medium resources in the WSN infrastructure. These non-optimal allocation policies reduce the energy consumed by the whole infrastructure and the total execution time.

Towards an unsupervised speaking style voice building framework: multi-style speaker diarization

Current text-to-speech systems are developed using studio-recorded speech in a neutral style or based on acted emotions. However, the proliferation of media sharing sites would allow developing a new generation of speech-based systems which could cope with spontaneous and styled speech. This paper proposes an architecture to deal with realistic recordings and carries out some experiments on unsupervised speaker diarization. In order to maximize the speaker purity of the clusters while keeping a high speaker coverage, the paper evaluates the F-measure of a diarization module, achieving high scores (>85%) especially when the clusters are longer than 30 seconds, even for the more spontaneous and expressive styles (such as talk shows or sports).

Multiprotocol Android Application for Smart Control and Monitoring in Buildings

This paper presents a multiprotocol mobile application for building automation which supports and enables the integration of the most representative control technologies such as KNX, LonWorks and X-10. The application includes a real-time monitoring service. Finally, advanced control functionalities based on gestures recognition and predefined scenes have been implemented. This application has been developed and tested in the Energy Efficiency Research Facility located at CeDInt-UPM, where electrical loads, blinds and HVAC and lighting systems can be controlled.

On the economics of energy consumption in 4G networks: the case of Spain

Reducing energy consumption is one of the main challenges in most countries. For example, European Member States agreed to reduce greenhouse gas (GHG) emissions by 20% in 2020 compared to 1990 levels (EC 2008). Considering each sector separately, ICTs account nowadays for 2% of total carbon emissions. This percentage will increase as the demand of communication services and applications steps up. At the same time, the expected evolution of ICT-based developments - smart buildings, smart grids and smart transportation systems among others - could result in the creation of energy-saving opportunities leading to global emission reductions (Labouze et al. 2008), although the amount of these savings is under debate (Falch 2010). The main development required in telecommunication networks ?one of the three major blocks of energy consumption in ICTs together with data centers and consumer equipment (Sutherland 2009) ? is the evolution of existing infrastructures into ultra-broadband networks, the so-called Next Generation Networks (NGN). Fourth generation (4G) mobile communications are the technology of choice to complete -or supplement- the ubiquitous deployment of NGN. The risk and opportunities involved in NGN roll-out are currently in the forefront of the economic and policy debate. However, the issue of which is the role of energy consumption in 4G networks seems absent, despite the fact that the economic impact of energy consumption arises as a key element in the cost analysis of this type of networks. Precisely, the aim of this research is to provide deeper insight on the energy consumption involved in the usage of a 4G network, its relationship with network main design features, and the general economic impact this would have in the capital and operational expenditures related with network deployment and usage.

Project based learning activities as a means of adapting conventional curricula to the demands of the 21st century aeronautical engineer: The design and building of the EYEFLY 1.

In this paper we report the process of designing and building the EYEFLY 1, a real UAS platform which has just performed its maiden flight. For the development of this aircraft, 30 groups of students from successive years at the Escuela Universitaria de Ingenier��a T��cnica Aeron��utica (EUITA) of the Universidad Polit��cnica de Madrid (UPM) carried out their compulsory End of Degree Project as a coordinated Project Based learning activity. Our conclusions clearly indicate that Project Based Learning activities can provide a valid complement to more conventional, theoretically-based, teaching methods. The combination of both approaches will allow us to maintain traditional but well-tested methods for providing our students with a sound knowledge of fundamental engineering disciplines and, at the same time, to introduce our students to exciting and relevant engineering situations and sceneries where social and business skills, such as communication skills, team-working or decision-taking, can be put into practice.

An Internet of Things approach for managing smart services provided by wearable devices.

The Internet of Things (IoT) is growing at a fast pace with new devices getting connected all the time. A new emerging group of these devices are the wearable devices, and Wireless Sensor Networks are a good way to integrate them in the IoT concept and bring new experiences to the daily life activities. In this paper we present an everyday life application involving a WSN as the base of a novel context-awareness sports scenario where physiological parameters are measured and sent to the WSN by wearable devices. Applications with several hardware components introduce the problem of heterogeneity in the network. In order to integrate different hardware platforms and to introduce a service-oriented semantic middleware solution into a single application, we propose the use of an Enterprise Service Bus (ESB) as a bridge for guaranteeing interoperability and integration of the different environments, thus introducing a semantic added value needed in the world of IoT-based systems. This approach places all the data acquired (e.g., via Internet data access) at application developers disposal, opening the system to new user applications. The user can then access the data through a wide variety of devices (smartphones, tablets, computers) and Operating Systems (Android, iOS, Windows, Linux, etc.).

Aplicaci��n de nuevas tecnolog��as en los sistemas de alumbrado

A medida que transcurre el tiempo la sociedad evoluciona, las ciudades crecen, se modernizan, mejoran su infraestructura y se ofrecen m��s y mejores servicios a sus ciudadanos. Esto ha hecho que durante muchos a��os las ciudades se hayan desarrollado sin pensar en lo que vendr�� m��s adelante, contaminando el medio ambiente y consumiendo mucha energ��a y de forma ineficiente. Ante esta situaci��n, y gracias a las innovaciones tecnol��gicas en materia de comunicaciones, se est��n adoptando medidas para dirigir la evoluci��n de las ciudades hacia un modelo de ciudad inteligente y sostenible. Las redes de comunicaciones constituyen uno de los pilares sobre los que se asienta la sociedad, que se encuentra siempre en contacto con su entorno. Cada vez m��s, se tiene una mayor necesidad de conocer lo que ocurre en el entorno en tiempo real solicitando informaci��n climatol��gica en una determinada ubicaci��n, permitiendo conocer el estado del tr��fico para elegir la ruta hacia el trabajo, saber el tiempo que tardar�� el autob��s en llegar a la parada, etc. Como ��stos, se podr��an citar muchos m��s ejemplos de necesidades y servicios que demandan hoy d��a la sociedad y que, seguramente, nadie pensaba que las iba a necesitar hace unos a��os. Muchos de estos servicios en tiempo real se consiguen gracias a las redes de sensores inal��mbricas. Consiste en desplegar una serie de diminutos sensores en una zona determinada con el objetivo de recoger la informaci��n del medio, procesarla y modelarla para que est�� disponible para los usuarios. Observando la tendencia seguida por las Tecnolog��as de la Informaci��n y de las Comunicaciones (TIC) se puede constatar una continua evoluci��n hacia los dispositivos embedidos, de cada vez m��s peque��o tama��o y menor consumo y, al mismo tiempo, con mayor capacidad de proceso y memoria y facilidad para las comunicaciones. Siguiendo esta l��nea, se est�� construyendo la ciudad inteligente con capacidad para pensar y tomar decisiones, pero hay que dotarla de cierto grado de eficiencia. Se trata de aprovechar los recursos de la naturaleza para crear fuentes de energ��as limpias e ilimitadas. Empleando las tecnolog��as oportunas para transformar, por ejemplo, la energ��a del Sol o la energ��a del viento en electricidad, se puede alcanzar el modelo de ciudad que se pretende. ABSTRACT. As time passes society evolves, cities grow, modernize, improve their infrastructure and offer more and better services to their citizens. This has made for many years cities have developed without thinking about what will come later , polluting the environment and high energy consuming and inefficient . Given this situation, and thanks to the Technological innovations in communications, is being taken to direct the evolution of cities towards a smart city model sustainable. Communication networks are one of the pillars on which society rests, which is always in contact with their environment. Increasingly, there is a greater need to know what happens in the real-time environment requesting weather information in a certain location , allowing know the traffic to choose the route to work , namely the time take the bus to get to the bus stop, etc. . As these, you could cite many more Examples of needs and services that society demands today and, surely, no one thought that was going to need a few years ago. Many of these real-time services are achieved through networks wireless sensors. Is to deploy a series of sensors in a tiny given area in order to collect information from the environment, process and shape it to make it available to users. Observing the trend followed by the Information Technology and Communications (ICT ) can finding an evolving toward embeded devices of increasingly small size and lower power consumption and at the same time, higher capacity process and memory ease communications. Following this line, is under construction with capacity smart city to think and make decisions, but you have to give it some degree of efficiency. It seeks to harness the resources of nature to create clean energy sources and unlimited. Using appropriate technologies to transform, for example, energy from the sun or wind energy into electricity, it can achieve the model city intended.

Design and Validation of an Optimized MB-OFDM Ultra Wideband Transceiver System

Esta tesis est�� incluida dentro del campo del campo de Multiband Orthogonal Frequency Division Multiplexing Ultra Wideband (MB-OFDM UWB), el cual ha adquirido una gran importancia en las comunicaciones inal��mbricas de alta tasa de datos en la ��ltima d��cada. UWB surgi�� con el objetivo de satisfacer la creciente demanda de conexiones inal��mbricas en interiores y de uso dom��stico, con bajo coste y alta velocidad. La disponibilidad de un ancho de banda grande, el potencial para alta velocidad de transmisi��n, baja complejidad y bajo consumo de energ��a, unido al bajo coste de implementaci��n, representa una oportunidad ��nica para que UWB se convierta en una soluci��n ampliamente utilizada en aplicaciones de Wireless Personal Area Network (WPAN). UWB est�� definido como cualquier transmisi��n que ocupa un ancho de banda de m��s de 20% de su frecuencia central, o m��s de 500 MHz. En 2002, la Comisi��n Federal de Comunicaciones (FCC) defini�� que el rango de frecuencias de transmisi��n de UWB legal es de 3.1 a 10.6 GHz, con una energ��a de transmisi��n de -41.3 dBm/Hz. Bajo las directrices de FCC, el uso de la tecnolog��a UWB puede aportar una enorme capacidad en las comunicaciones de corto alcance. Considerando las ecuaciones de capacidad de Shannon, incrementar la capacidad del canal requiere un incremento lineal en el ancho de banda, mientras que un aumento similar de la capacidad de canal requiere un aumento exponencial en la energ��a de transmisi��n. En los ��ltimos a��os, s diferentes desarrollos del UWB han sido extensamente estudiados en diferentes ��reas, entre los cuales, el protocolo de comunicaciones inal��mbricas MB-OFDM UWB est�� considerado como la mejor elecci��n y ha sido adoptado como est��ndar ISO/IEC para los WPANs. Combinando la modulaci��n OFDM y la transmisi��n de datos utilizando las t��cnicas de salto de frecuencia, el sistema MB-OFDM UWB es capaz de soportar tasas de datos con que pueden variar de los 55 a los 480 Mbps, alcanzando una distancia m��xima de hasta 10 metros. Se esperara que la tecnolog��a MB-OFDM tenga un consumo energ��tico muy bajo copando un are muy reducida en silicio, proporcionando soluciones de bajo coste que satisfagan las demandas del mercado. Para cumplir con todas estas expectativas, el desarrollo y la investigaci��n del MBOFDM UWB deben enfrentarse a varios retos, como son la sincronizaci��n de alta sensibilidad, las restricciones de baja complejidad, las estrictas limitaciones energ��ticas, la escalabilidad y la flexibilidad. Tales retos requieren un procesamiento digital de la se��al de ��ltima generaci��n, capaz de desarrollar sistemas que puedan aprovechar por completo las ventajas del espectro UWB y proporcionar futuras aplicaciones inal��mbricas en interiores. Esta tesis se centra en la completa optimizaci��n de un sistema de transceptor de banda base MB-OFDM UWB digital, cuyo objetivo es investigar y dise��ar un subsistema de comunicaci��n inal��mbrica para la aplicaci��n de las Redes de Sensores Inal��mbricas Visuales. La complejidad inherente de los procesadores FFT/IFFT y el sistema de sincronizaci��n as�� como la alta frecuencia de operaci��n para todos los elementos de procesamiento, se convierten en el cuello de la botella para el dise��o y la implementaci��n del sistema de UWB digital en base de banda basado en MB-OFDM de baja energ��a. El objetivo del transceptor propuesto es conseguir baja energ��a y baja complejidad bajo la premisa de un alto rendimiento. Las optimizaciones est��n realizadas tanto a nivel algor��tmico como a nivel arquitectural para todos los elementos del sistema. Una arquitectura hardware eficiente en consumo se propone en primer lugar para aquellos m��dulos correspondientes a n��cleos de computaci��n. Para el procesado de la Transformada R��pida de Fourier (FFT/IFFT), se propone un algoritmo mixed-radix, basado en una arquitectura con pipeline y se ha desarrollado un m��dulo de Decodificador de Viterbi (VD) equilibrado en coste-velocidad con el objetivo de reducir el consumo energ��tico e incrementar la velocidad de procesamiento. Tambi��n se ha implementado un correlador signo-bit simple basado en la sincronizaci��n del tiempo de s��mbolo es presentado. Este correlador es usado para detectar y sincronizar los paquetes de OFDM de forma robusta y precisa. Para el desarrollo de los subsitemas de procesamiento y realizar la integraci��n del sistema completo se han empleado tecnolog��as de ��ltima generaci��n. El dispositivo utilizado para el sistema propuesto es una FPGA Virtex 5 XC5VLX110T del fabricante Xilinx. La validaci��n el propuesta para el sistema transceptor se ha implementado en dicha placa de FPGA. En este trabajo se presenta un algoritmo, y una arquitectura, dise��ado con filosof��a de co-dise��o hardware/software para el desarrollo de sistemas de FPGA complejos. El objetivo principal de la estrategia propuesta es de encontrar una metodolog��a eficiente para el dise��o de un sistema de FPGA configurable optimizado con el empleo del m��nimo esfuerzo posible en el sistema de procedimiento de verificaci��n, por tanto acelerar el periodo de desarrollo del sistema. La metodolog��a de co-dise��o presentada tiene la ventaja de ser f��cil de usar, contiene todos los pasos desde la propuesta del algoritmo hasta la verificaci��n del hardware, y puede ser ampliamente extendida para casi todos los tipos de desarrollos de FPGAs. En este trabajo se ha desarrollado s��lo el sistema de transceptor digital de banda base por lo que la comprobaci��n de se��ales transmitidas a trav��s del canal inal��mbrico en los entornos reales de comunicaci��n sigue requiriendo componentes RF y un front-end anal��gico. No obstante, utilizando la metodolog��a de co-simulaci��n hardware/software citada anteriormente, es posible comunicar el sistema de transmisor y el receptor digital utilizando los modelos de canales propuestos por IEEE 802.15.3a, implementados en MATLAB. Por tanto, simplemente ajustando las caracter��sticas de cada modelo de canal, por ejemplo, un incremento del retraso y de la frecuencia central, podemos estimar el comportamiento del sistema propuesto en diferentes escenarios y entornos. Las mayores contribuciones de esta tesis son: ��� Se ha propuesto un nuevo algoritmo 128-puntos base mixto FFT usando la arquitectura pipeline multi-ruta. Los complejos multiplicadores para cada etapa de procesamiento son dise��ados usando la arquitectura modificada shiftadd. Los sistemas word length y twiddle word length son comparados y seleccionados bas��ndose en la se��al para cuantizaci��n del SQNR y el an��lisis de energ��as. ��� El desempe��o del procesador IFFT es analizado bajo diferentes situaciones aritm��ticas de bloques de punto flotante (BFP) para el control de desbordamiento, por tanto, para encontrar la arquitectura perfecta del algoritmo IFFT basado en el procesador FFT propuesto. ��� Para el sistema de receptor MB-OFDM UWB se ha empleado una sincronizaci��n del tiempo innovadora, de baja complejidad y esquema de compensaci��n, que consiste en funciones de Detector de Paquetes (PD) y Estimaci��n del Offset del tiempo. Simplificando el cross-correlation y maximizar las funciones probables solo a sign-bit, la complejidad computacional se ve reducida significativamente. ��� Se ha propuesto un sistema de decodificadores Viterbi de 64 estados de decisi��n-d��bil usando velocidad base-4 de arquitectura suma-comparaselecciona. El algoritmo Two-pointer Even tambi��n es introducido en la unidad de rastreador de origen con el objetivo de conseguir la eficiencia en el hardware. ��� Se han integrado varias tecnolog��as de ��ltima generaci��n en el completo sistema transceptor basebanda , con el objetivo de implementar un sistema de comunicaci��n UWB altamente optimizado. ��� Un dise��o de flujo mejorado es propuesto para el complejo sistema de implementaci��n, el cual puede ser usado para dise��os de Cadena de puertas de campo programable general (FPGA). El dise��o mencionado no s��lo reduce dram��ticamente el tiempo para la verificaci��n funcional, sino tambi��n provee un an��lisis autom��tico como los errores del retraso del output para el sistema de hardware implementado. ��� Un ambiente de comunicaci��n virtual es establecido para la validaci��n del propuesto sistema de transceptores MB-OFDM. Este m��todo es provisto para facilitar el uso y la conveniencia de analizar el sistema digital de basebanda sin parte frontera anal��gica bajo diferentes ambientes de comunicaci��n. Esta tesis doctoral est�� organizada en seis cap��tulos. En el primer cap��tulo se encuentra una breve introducci��n al campo del UWB, tanto relacionado con el proyecto como la motivaci��n del desarrollo del sistema de MB-OFDM. En el cap��tulo 2, se presenta la informaci��n general y los requisitos del protocolo de comunicaci��n inal��mbrica MBOFDM UWB. En el cap��tulo 3 se habla de la arquitectura del sistema de transceptor digital MB-OFDM de banda base . El dise��o del algoritmo propuesto y la arquitectura para cada elemento del procesamiento est�� detallado en este cap��tulo. Los retos de dise��o del sistema que involucra un compromiso de discusi��n entre la complejidad de dise��o, el consumo de energ��a, el coste de hardware, el desempe��o del sistema, y otros aspectos. En el cap��tulo 4, se ha descrito la co-dise��ada metodolog��a de hardware/software. Cada parte del flujo del dise��o ser�� detallado con algunos ejemplos que se ha hecho durante el desarrollo del sistema. Aprovechando esta estrategia de dise��o, el procedimiento de comunicaci��n virtual es llevado a cabo para probar y analizar la arquitectura del transceptor propuesto. Los resultados experimentales de la co-simulaci��n y el informe sint��tico de la implementaci��n del sistema FPGA son reflejados en el cap��tulo 5. Finalmente, en el cap��tulo 6 se incluye las conclusiones y los futuros proyectos, y tambi��n los resultados derivados de este proyecto de doctorado. ABSTRACT In recent years, the Wireless Visual Sensor Network (WVSN) has drawn great interest in wireless communication research area. They enable a wealth of new applications such as building security control, image sensing, and target localization. However, nowadays wireless communication protocols (ZigBee, Wi-Fi, and Bluetooth for example) cannot fully satisfy the demands of high data rate, low power consumption, short range, and high robustness requirements. New communication protocol is highly desired for such kind of applications. The Ultra Wideband (UWB) wireless communication protocol, which has increased in importance for high data rate wireless communication field, are emerging as an important topic for WVSN research. UWB has emerged as a technology that offers great promise to satisfy the growing demand for low-cost, high-speed digital wireless indoor and home networks. The large bandwidth available, the potential for high data rate transmission, and the potential for low complexity and low power consumption, along with low implementation cost, all present a unique opportunity for UWB to become a widely adopted radio solution for future Wireless Personal Area Network (WPAN) applications. UWB is defined as any transmission that occupies a bandwidth of more than 20% of its center frequency, or more than 500 MHz. In 2002, the Federal Communications Commission (FCC) has mandated that UWB radio transmission can legally operate in the range from 3.1 to 10.6 GHz at a transmitter power of ���41.3 dBm/Hz. Under the FCC guidelines, the use of UWB technology can provide enormous capacity over short communication ranges. Considering Shannon���s capacity equations, increasing the channel capacity requires linear increasing in bandwidth, whereas similar channel capacity increases would require exponential increases in transmission power. In recent years, several different UWB developments has been widely studied in different area, among which, the MB-OFDM UWB wireless communication protocol is considered to be the leading choice and has recently been adopted in the ISO/IEC standard for WPANs. By combing the OFDM modulation and data transmission using frequency hopping techniques, the MB-OFDM UWB system is able to support various data rates, ranging from 55 to 480 Mbps, over distances up to 10 meters. The MB-OFDM technology is expected to consume very little power and silicon area, as well as provide low-cost solutions that can satisfy consumer market demands. To fulfill these expectations, MB-OFDM UWB research and development have to cope with several challenges, which consist of high-sensitivity synchronization, low- complexity constraints, strict power limitations, scalability, and flexibility. Such challenges require state-of-the-art digital signal processing expertise to develop systems that could fully take advantages of the UWB spectrum and support future indoor wireless applications. This thesis focuses on fully optimization for the MB-OFDM UWB digital baseband transceiver system, aiming at researching and designing a wireless communication subsystem for the Wireless Visual Sensor Networks (WVSNs) application. The inherent high complexity of the FFT/IFFT processor and synchronization system, and high operation frequency for all processing elements, becomes the bottleneck for low power MB-OFDM based UWB digital baseband system hardware design and implementation. The proposed transceiver system targets low power and low complexity under the premise of high performance. Optimizations are made at both algorithm and architecture level for each element of the transceiver system. The low-power hardwareefficient structures are firstly proposed for those core computation modules, i.e., the mixed-radix algorithm based pipelined architecture is proposed for the Fast Fourier Transform (FFT/IFFT) processor, and the cost-speed balanced Viterbi Decoder (VD) module is developed, in the aim of lowering the power consumption and increasing the processing speed. In addition, a low complexity sign-bit correlation based symbol timing synchronization scheme is presented so as to detect and synchronize the OFDM packets robustly and accurately. Moreover, several state-of-the-art technologies are used for developing other processing subsystems and an entire MB-OFDM digital baseband transceiver system is integrated. The target device for the proposed transceiver system is Xilinx Virtex 5 XC5VLX110T FPGA board. In order to validate the proposed transceiver system in the FPGA board, a unified algorithm-architecture-circuit hardware/software co-design environment for complex FPGA system development is presented in this work. The main objective of the proposed strategy is to find an efficient methodology for designing a configurable optimized FPGA system by using as few efforts as possible in system verification procedure, so as to speed up the system development period. The presented co-design methodology has the advantages of easy to use, covering all steps from algorithm proposal to hardware verification, and widely spread for almost all kinds of FPGA developments. Because only the digital baseband transceiver system is developed in this thesis, the validation of transmitting signals through wireless channel in real communication environments still requires the analog front-end and RF components. However, by using the aforementioned hardware/software co-simulation methodology, the transmitter and receiver digital baseband systems get the opportunity to communicate with each other through the channel models, which are proposed from the IEEE 802.15.3a research group, established in MATLAB. Thus, by simply adjust the characteristics of each channel model, e.g. mean excess delay and center frequency, we can estimate the transmission performance of the proposed transceiver system through different communication situations. The main contributions of this thesis are: ��� A novel mixed radix 128-point FFT algorithm by using multipath pipelined architecture is proposed. The complex multipliers for each processing stage are designed by using modified shift-add architectures. The system wordlength and twiddle word-length are compared and selected based on Signal to Quantization Noise Ratio (SQNR) and power analysis. ��� IFFT processor performance is analyzed under different Block Floating Point (BFP) arithmetic situations for overflow control, so as to find out the perfect architecture of IFFT algorithm based on the proposed FFT processor. ��� An innovative low complex timing synchronization and compensation scheme, which consists of Packet Detector (PD) and Timing Offset Estimation (TOE) functions, for MB-OFDM UWB receiver system is employed. By simplifying the cross-correlation and maximum likelihood functions to signbit only, the computational complexity is significantly reduced. ��� A 64 state soft-decision Viterbi Decoder system by using high speed radix-4 Add-Compare-Select architecture is proposed. Two-pointer Even algorithm is also introduced into the Trace Back unit in the aim of hardware-efficiency. ��� Several state-of-the-art technologies are integrated into the complete baseband transceiver system, in the aim of implementing a highly-optimized UWB communication system. ��� An improved design flow is proposed for complex system implementation which can be used for general Field-Programmable Gate Array (FPGA) designs. The design method not only dramatically reduces the time for functional verification, but also provides automatic analysis such as errors and output delays for the implemented hardware systems. ��� A virtual communication environment is established for validating the proposed MB-OFDM transceiver system. This methodology is proved to be easy for usage and convenient for analyzing the digital baseband system without analog frontend under different communication environments. This PhD thesis is organized in six chapters. In the chapter 1 a brief introduction to the UWB field, as well as the related work, is done, along with the motivation of MBOFDM system development. In the chapter 2, the general information and requirement of MB-OFDM UWB wireless communication protocol is presented. In the chapter 3, the architecture of the MB-OFDM digital baseband transceiver system is presented. The design of the proposed algorithm and architecture for each processing element is detailed in this chapter. Design challenges of such system involve trade-off discussions among design complexity, power consumption, hardware cost, system performance, and some other aspects. All these factors are analyzed and discussed. In the chapter 4, the hardware/software co-design methodology is proposed. Each step of this design flow will be detailed by taking some examples that we met during system development. Then, taking advantages of this design strategy, the Virtual Communication procedure is carried out so as to test and analyze the proposed transceiver architecture. Experimental results from the co-simulation and synthesis report of the implemented FPGA system are given in the chapter 5. The chapter 6 includes conclusions and future work, as well as the results derived from this PhD work.

ICT: an empowering tool for social enterprises

In recent years new models for organizations working on poverty alleviation have emerged. One of them, the social enterprise, has attracted the attention of both academics and practitioners all over the world. Even if defined in different ways depending on the context, this model has an enormous potential to generate social benefits and to promote local agency and private initiative in poverty alleviation.