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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Zero energy buildings : theoretical investigation and applied analysis for the design of zero energy building in hot climate countries

Pittakaras, Paris January 2015 (has links)
Problem description: The buildings consume significant amounts of energy and are therefore major contributors to the overall CO2 emissions at the present time. The reduction of energy consumption in buildings is a major contribution to the overall control of global warming and to the improvement of sustainability. These reductions are essential as the world faces economic and energy crisis. An important key to the world’s energy problem is sustainable development. Taking the island of Cyprus as a case study, this thesis explores the different building categories and types, analyse building energy models and propose guidelines for the success development of Zero energy buildings in hot climates without compromising the comfort levels of the buildings. Purpose: The ultimate target is to be able to design and operate a building which requires no fossil fuel consumption – the so called “zero energy/carbon (emissions)” building. It is important for all countries to set a national goal in order to achieve zero energy consumption in the building sector and reduce the energy demands. Method: Through the theoretical research the project explored the causes of the problem of building energy, the different types of buildings, the definitions of zero energy buildings in various countries, regulations and standards concerning the buildings energy and all the available technology, methods and materials that can be used in the building sector. In this way the analysis presents the needs of the project and the point of focus during the practical part of the research with simulation of building models. The practical part of the project was the simulation of different building models in order to apply and check the theoretical findings and finally reach conclusions on the development of Zero energy buildings in hot climate countries. During the building simulation a variety of parameters such as the weather, the orientation, the shading methods, the insulation methods, the buildings materials, the glazing, the HVAC systems and building operation profiles were checked in order to find the appropriate combination of factors and achieve the zero energy building goals. Conclusions: This new approach to zero energy building, gives a new perspective to the energy consumption of the building and the indoor environment while also taking environmental impact from the building sector into account. This change in approach is a crucial part of the overall problem of how to achieve the ultimate goal of Zero Energy Buildings and how to convert buildings into “producers” of energy and help solve the world energy problem/crisis.
2

Návrh dispozičního řešení vícepodlažního bytového domu na území města České Budějovice / Proposed layout of a multi-storey apartment building on the territory of the town of České Budějovice.

SMUTNÁ, Michaela January 2011 (has links)
The thesis deals with a proposed layout of a multi-storey apartment building on the territory of the town of České Budějovice. The thesis contains a literary overview to inform the reader about the issues of design documents, analysis of the land use plan for the corporate town of České Budějovice in connection with the building location and, last but not least, related design documents in agreement with the applicable decree. The objective of this thesis was to develop the design documents meeting the low energy consumption standard, i.e. meeting all current requirements for modern and energy-saving construction projects, in terms of the appearance, employed technologies and materials. An integral part of the results is a placement of the project in a suitable location, as outlined by the land use plan. The thesis is concluded with an evaluation of the architectural and structural solution and of the selected materials in respect to the low energy consumption standard of the building.
3

Low Energy GPS Positioning : A device-server approach / Lågenergipositionering med GPS

Szilassy, Martin, Örn, Daniel January 2015 (has links)
GPS is widely used for localization and tracking, however traditional GPS receivers consume too much energy for many applications. This thesis implements and evaluates the performance of a low energy GPS solution, including a working hardware prototype, that reduces energy consumption significantly. The prototype operates for 2 years on a coin cell battery, sampling every minute. The corresponding time for a traditional receiver is 2 days. The main difference is that a traditional receiver requires 30 seconds of data to estimate a position; this solution only requires 2 milliseconds of data, a reduction of a factor 15 000. The solution consists of a portable device, sampling the GPS signal, and server software that utilizes Doppler navigation and Coarse Time Navigation to estimate positions. The median positioning error is at most 38 meters in our tests. We expect that this solution will enable positioning for billions of devices in the near future.
4

Energy efficient instruction decoding in application: Specific instruction - set processors / Αποκωδικοποίηση εντολών για χαμηλή κατανάλωση ενέργειας σε επεξεργαστές συνόλου εντολών ειδικού σκοπού

Κάργας, Χρήστος 04 September 2013 (has links)
With commercial processor design tools, a designer can quickly design a C- programmable ASIP for a specific application domain. There are several such ASIPs available for both wireless (UWB baseband processing), encryption, and biomedical processing (particularly for ECG beat detection). In traditional CPUs and DSPs the impact of the instruction-set definition and the complexity of the instruction decoder can be substantial, especially in terms of power consumption. Fully orthogonal VLIW processors, do not incur the cost of an instruction decoder that severely. Instead the instruction word becomes very large, thereby shifting the (power-)cost to the program memory or instruction cache. For the purposes of this thesis a SIMD processor is developed and is compared to a soft-SIMD to observe its area, performance and energy efficiency for a bioimaging benchmark and how the processor description in the ASIP language nML, defines the generated HDL. This SIMD processor is turned into orthogonal and using iterative experiments it is investigated, what is the impact on power while manipulating the instruction-set architecture in combination with the program memory size. It is also investigated how instruction-set re-configuration can be exploited to improve power efficiency. Using this investigation guidelines for low-power ASIP design can be produced. / Με τη σύγχρονη τεχνολογία σχεδιασμού επεξεργαστών, ο σχεδιαστής μπορεί με ευκολία να σχεδιάσει ένα προγραμματιζόμενο Επεξεργαστή Συνόλου Εντολών Ειδικού Σκοπού (ASIP - Application-Specific Instruction-set Processor) για ένα συγκεκριμένο εύρος εφαρμογών. Υπάρχουν διάφοροι τέτοιοι επεξεργαστές διαθέσιμοι για ασύρματες εφαρμογές, κρυπτογράφηση και βιοϊατρικές εφαρμογές (π.χ. στον αλγόριθμο εντοπισμού χτύπου ηλεκτροκαρδιογραφήματος). Στους παραδοσιακούς επεξεργαστές και επεξεργαστές σήματος (DSP - Digital Signal Processor) ο ορισμός του συνόλου εντολών και η πολυπλοκότητα έχουν μεγάλη επίδραση, ειδικά στην κατανάλωση ισχύος. Μία πιθανή λύση σε αυτό το πρόβλημα είναι οι ορθογώνιοι επεξεργαστές μεγάλου μεγέθους λέξης εντολής (VLIW - Very Large Instruction Word). Με τον όρο ορθογώνιο επεξεργαστή, ορίζεται ένας επεξεργαστής οριζόντιου σύνολου εντολών, άρα ένας επεξεργαστής στον οποίο μπορεί να υπάρξει κάθε διαθέσιμος συνδυασμός μεταξύ των διαθέσιμων εντολών και των μεθόδων διευθυνσιοδότησης για πρόσβαση στη μνήμη και το αρχείο καταχωρητών. Οι ορθογώνιοι επεξεργαστές δεν επιβαρύνουν τόσο τον αποκωδικοποιητή εντολών. Αντί αυτού το μέγεθος της λέξης της εντολής γίνεται πολύ μεγάλο, και έτσι μετατίθεται το ενεργειακό κόστος στην μνήμη εντολών προγράμματος (program memory )ή την κρυφή μνήμη εντολών προγράμματος (instruction cache). Για τους σκοπούς αυτής της διπλωματικής εργασίας, αναπτύχθηκε ένας επεξεργαστής SIMD, ο οποίος συγκρίνεται με έναν soft-SIMD για να μελετηθούν η απαιτούμενη περιοχή στο ενσωματωμένο, επιδόσεις και κατανάλωση ενέργειας για μία βιοϊατρική εφαρμογή, καθώς και το πως η περιγραφή ενός επεξεργαστή στη γλώσσα περιγραφής επεξεργαστών ASIP nML ορίζει την παραγούμενη γλώσσα περιγραφής υλικού (HDL - Hardware Description Language). Ο επεξεργαστής αυτός μετατρέπεται σε ορθογώνιο, και με τη χρήση επαναληπτικών πειραμάτων μελετάται η επίδραση στην κατανάλωση ενέργειας κατά τη διάρκεια αλλαγών στην αρχιτεκτονική του συνόλου εντολών και του μεγέθους της μνήμης εντολών προγράμματος. Ακόμη μελετάται πως μπορεί να εκμεταλλευτεί ο σχεδιαστής την αναδιάρθρωση του συνόλου εντολών για να βελτιώσει την κατανάλωση ενέργειας.
5

Desempenho lumínico em edificação escolar com estratégias sustentáveis e bioclimáticas : um estudo de caso

Krum, Christiane Cunha January 2011 (has links)
Frente ao desenfreado desenvolvimento da sociedade nas suas diversas esferas, busca-se novas maneiras de habitar o planeta, de forma a preservá-lo para as futuras gerações. Uma das vertentes nas quais o homem pode intervir e, assim, ajudar a preservar os recursos naturais do planeta, diz respeito à busca por economia energética. Em edificações de uso prolongado e onde são desenvolvidas atividades visuais intensas, o uso da luz natural é de extrema valia, não apenas resultando em economia de energia elétrica, mas também contribuindo para o conforto ambiental e bem estar de seus usuários através dos benefícios proporcionados por esta luz. Portanto, o uso da luz natural sendo complementada pela luz artificial é de profunda importância para o bom desempenho lumínico da edificação. Fruto dos trabalhos desenvolvidos pelo grupo de pesquisa em Edificações e Comunidades Sustentáveis do NORIE/UFRGS, a edificação escolar analisada nesta pesquisa foi projetada a partir de estratégias sustentáveis e bioclimáticas. Esta pesquisa tem como objetivo avaliar o desempenho lumínico de uma sala de aula da edificação supracitada, para, assim, proporcionar considerações acerca das decisões projetuais tomadas. A metodologia utilizada para a obtenção destas informações consistiu na análise das intenções projetuais dos autores da edificação, no levantamento das características físicas e construtivas da escola e em medições lumínicas realizadas ao longo de um dia, em datas próximas aos solstícios e equinócios, no interior e no exterior da edificação. E, para verificar a eficiência de alguns elementos da edificação e propor melhorias de forma a incrementar o seu desempenho lumínico, foram realizadas simulações da sala de aula. A partir dos resultados gerados nesta pesquisa pretende-se não apenas fornecer informações sobre o desempenho lumínico desta edificação, como levantar questões que poderão embasar futuros projetos preocupados em fazer um melhor uso desta fonte natural, gratuita e de qualidade: a luz natural. / New manners on how to inhabit the planet are sought due to the increasing society development, in order to preserve it for the future generation. The seeking for low-energy consumption alternatives is one of the key issues the man can intervene in order to preserve earth´s natural resources. The usage of natural light is extremely valuable in edifications where intensive visual activities are developed; not only resulting in electric energy savings but also contributing for the environmental comfort and users´ well-being through the benefits provided by this light. Hence, the natural light usage complemented by the artificial light has a great importance in the edification´s luminous performance. The scholar edification analyzed by this research was projected with sustainable and bioclimatic strategies, based on information developed by NORIE/UFRGS research group on Sustainable Edifications and Communities. This research’s objective is to evaluate the luminous performance of one of the scholar edification´s classroom in order to provide considerations in relation to the project´s decisions. The selected methodology for these information gathering was based on the edification authors´ project intensions, the physical and constructive school´s characteristics, and the luminous measurements taken along a hole day. These measurements were taken on dates close to solstices and equinoxes, in the edification´s interior and exterior. Classroom model simulations were developed in order to verify some building´s elements efficiency and to propose improvements for its luminous performance. The research´s results intends to provide relevant information about this particular edification´s luminous performance; and also to rise useful knowledge for future projects regarding daylight usage, a free and natural source of energy.
6

Desempenho lumínico em edificação escolar com estratégias sustentáveis e bioclimáticas : um estudo de caso

Krum, Christiane Cunha January 2011 (has links)
Frente ao desenfreado desenvolvimento da sociedade nas suas diversas esferas, busca-se novas maneiras de habitar o planeta, de forma a preservá-lo para as futuras gerações. Uma das vertentes nas quais o homem pode intervir e, assim, ajudar a preservar os recursos naturais do planeta, diz respeito à busca por economia energética. Em edificações de uso prolongado e onde são desenvolvidas atividades visuais intensas, o uso da luz natural é de extrema valia, não apenas resultando em economia de energia elétrica, mas também contribuindo para o conforto ambiental e bem estar de seus usuários através dos benefícios proporcionados por esta luz. Portanto, o uso da luz natural sendo complementada pela luz artificial é de profunda importância para o bom desempenho lumínico da edificação. Fruto dos trabalhos desenvolvidos pelo grupo de pesquisa em Edificações e Comunidades Sustentáveis do NORIE/UFRGS, a edificação escolar analisada nesta pesquisa foi projetada a partir de estratégias sustentáveis e bioclimáticas. Esta pesquisa tem como objetivo avaliar o desempenho lumínico de uma sala de aula da edificação supracitada, para, assim, proporcionar considerações acerca das decisões projetuais tomadas. A metodologia utilizada para a obtenção destas informações consistiu na análise das intenções projetuais dos autores da edificação, no levantamento das características físicas e construtivas da escola e em medições lumínicas realizadas ao longo de um dia, em datas próximas aos solstícios e equinócios, no interior e no exterior da edificação. E, para verificar a eficiência de alguns elementos da edificação e propor melhorias de forma a incrementar o seu desempenho lumínico, foram realizadas simulações da sala de aula. A partir dos resultados gerados nesta pesquisa pretende-se não apenas fornecer informações sobre o desempenho lumínico desta edificação, como levantar questões que poderão embasar futuros projetos preocupados em fazer um melhor uso desta fonte natural, gratuita e de qualidade: a luz natural. / New manners on how to inhabit the planet are sought due to the increasing society development, in order to preserve it for the future generation. The seeking for low-energy consumption alternatives is one of the key issues the man can intervene in order to preserve earth´s natural resources. The usage of natural light is extremely valuable in edifications where intensive visual activities are developed; not only resulting in electric energy savings but also contributing for the environmental comfort and users´ well-being through the benefits provided by this light. Hence, the natural light usage complemented by the artificial light has a great importance in the edification´s luminous performance. The scholar edification analyzed by this research was projected with sustainable and bioclimatic strategies, based on information developed by NORIE/UFRGS research group on Sustainable Edifications and Communities. This research’s objective is to evaluate the luminous performance of one of the scholar edification´s classroom in order to provide considerations in relation to the project´s decisions. The selected methodology for these information gathering was based on the edification authors´ project intensions, the physical and constructive school´s characteristics, and the luminous measurements taken along a hole day. These measurements were taken on dates close to solstices and equinoxes, in the edification´s interior and exterior. Classroom model simulations were developed in order to verify some building´s elements efficiency and to propose improvements for its luminous performance. The research´s results intends to provide relevant information about this particular edification´s luminous performance; and also to rise useful knowledge for future projects regarding daylight usage, a free and natural source of energy.
7

Desempenho lumínico em edificação escolar com estratégias sustentáveis e bioclimáticas : um estudo de caso

Krum, Christiane Cunha January 2011 (has links)
Frente ao desenfreado desenvolvimento da sociedade nas suas diversas esferas, busca-se novas maneiras de habitar o planeta, de forma a preservá-lo para as futuras gerações. Uma das vertentes nas quais o homem pode intervir e, assim, ajudar a preservar os recursos naturais do planeta, diz respeito à busca por economia energética. Em edificações de uso prolongado e onde são desenvolvidas atividades visuais intensas, o uso da luz natural é de extrema valia, não apenas resultando em economia de energia elétrica, mas também contribuindo para o conforto ambiental e bem estar de seus usuários através dos benefícios proporcionados por esta luz. Portanto, o uso da luz natural sendo complementada pela luz artificial é de profunda importância para o bom desempenho lumínico da edificação. Fruto dos trabalhos desenvolvidos pelo grupo de pesquisa em Edificações e Comunidades Sustentáveis do NORIE/UFRGS, a edificação escolar analisada nesta pesquisa foi projetada a partir de estratégias sustentáveis e bioclimáticas. Esta pesquisa tem como objetivo avaliar o desempenho lumínico de uma sala de aula da edificação supracitada, para, assim, proporcionar considerações acerca das decisões projetuais tomadas. A metodologia utilizada para a obtenção destas informações consistiu na análise das intenções projetuais dos autores da edificação, no levantamento das características físicas e construtivas da escola e em medições lumínicas realizadas ao longo de um dia, em datas próximas aos solstícios e equinócios, no interior e no exterior da edificação. E, para verificar a eficiência de alguns elementos da edificação e propor melhorias de forma a incrementar o seu desempenho lumínico, foram realizadas simulações da sala de aula. A partir dos resultados gerados nesta pesquisa pretende-se não apenas fornecer informações sobre o desempenho lumínico desta edificação, como levantar questões que poderão embasar futuros projetos preocupados em fazer um melhor uso desta fonte natural, gratuita e de qualidade: a luz natural. / New manners on how to inhabit the planet are sought due to the increasing society development, in order to preserve it for the future generation. The seeking for low-energy consumption alternatives is one of the key issues the man can intervene in order to preserve earth´s natural resources. The usage of natural light is extremely valuable in edifications where intensive visual activities are developed; not only resulting in electric energy savings but also contributing for the environmental comfort and users´ well-being through the benefits provided by this light. Hence, the natural light usage complemented by the artificial light has a great importance in the edification´s luminous performance. The scholar edification analyzed by this research was projected with sustainable and bioclimatic strategies, based on information developed by NORIE/UFRGS research group on Sustainable Edifications and Communities. This research’s objective is to evaluate the luminous performance of one of the scholar edification´s classroom in order to provide considerations in relation to the project´s decisions. The selected methodology for these information gathering was based on the edification authors´ project intensions, the physical and constructive school´s characteristics, and the luminous measurements taken along a hole day. These measurements were taken on dates close to solstices and equinoxes, in the edification´s interior and exterior. Classroom model simulations were developed in order to verify some building´s elements efficiency and to propose improvements for its luminous performance. The research´s results intends to provide relevant information about this particular edification´s luminous performance; and also to rise useful knowledge for future projects regarding daylight usage, a free and natural source of energy.
8

La méthode des saisons climatiques : stratégie passive de conception architecturale de bâtiments basse consommation énergétique en climat très chaud / The climatic seasons method : a passive design strategy for low energy consumption buildings in very hot climate

Yusta Garcia, Ferran 19 September 2018 (has links)
Si un concepteur, architecte ou ingénieur, veut concevoir un logement de basse consommation et le site du projet se trouve dans une région au climat froid, les réponses sont nombreuses et la littérature scientifique très abondante. Si le site de notre projet se situe en climat chaud, voir très chaud, le nombre de méthodes simples pour concevoir une maison de basse consommation diminue drastiquement. La solution la plus habituelle des concepteurs non initiés à la basse consommation est de faire appel à un ingénieur d’un bureau d’études énergétiques, qui saura proposer des simulations à partir d’un modèle thermique-dynamique et anticiper la consommation du modèle. La mission d’un bureau d’études a un certain coût, et ses services ne peuvent pas être accessibles à tous les projets. Ainsi, des milliers d’architectes en climat chaud proposent des projets inspirés des références lointaines ou des réalisations non adaptées sans les conseils d’un spécialiste de l’énergie du bâtiment. Ces projets, très énergivores, continuent à croître sans cesse. Pour tous ces concepteurs des projets de taille modeste nous proposons dans cette étude une méthode facile, efficace et accessible à tous permettant de prendre conscience des enjeux bioclimatiques et les options architecturales qui existent pour réussir un projet de basse consommation, puis de le défendre auprès de ses commanditaires. En nous appuyant sur les informations en ligne accessibles à tous, nous proposons une méthode basée sur l’utilisation des degrés-jour de refroidissement et de chauffage. Une série de simulations robustes sur un modèle thermique dynamique générique fourni des résultats qui pourront être interprétables par les concepteurs et projetés sur leurs propres conceptions.La première partie de ce document analyse la construction et la culture en climat chaud: méthodes de classification climatique, les phénomènes physiques les plus significatifs en lien avec la basse consommation,et les notions de confort et température ressentie. En suite, nous proposons un outil d’aide à la conception : la Méthode des Saisons Climatiques, une méthode basée sur un concept très simple : l’ouverture ou fermeture de la maison à l’extérieur en fonction des conditions extérieures quantifiée par les degrés-jour du site. Elle permet de faire une classification climatique du site très orientée vers la conception bioclimatique. Elle base le classement d’un site selon des journées types, S1 à S6, selon jour/nuit froid/froide, tempéré/froide, tempéré/tempérée, chaud/froide, chaud/tempérée et chaud/chaude respectivement. Cette nouvelle classification peu ts’appliquer à tous les climats de la Planète. Une période de l’année continue avec une même journée type donne lieu a une Saison Climatique. Chaque Saison climatique aura des spécificités architecturales propres,et parfois contradictoires entre deux saisons climatiques différentes. L’objectif est de trouver la combinaison architecturale la plus efficace pour une période annuelle complète.Des modélisations Energy+ seront faites pour ces 6 journées types ainsi que pour une période annuelle dans une ville au climat très chaud : Dubaï. Des actions architecturales sont évaluées avec un modèle thermique dynamique.Les actions architecturales seront classées par efficacité énergétique et par temps de retour surinvestissement . Deux maisons idéales par journée type seront proposées : la maison la plus performante et la maison la plus rentable. Une méthode de combinaison d’actions architecturales permettra de trouver une combinaison cohérente d’actions en fonction du climat annuel d’un site. Ensuite nous proposerons les caractéristiques communes, un socle commun, de la maison en climat très chaud de la région du Moyen Orient. / The last 25 years have been ground-breaking in architectural design on low energy consumption in cold climate, mainly in north-western cultures. For an architect today, the method to design a passive house in cold weather and the choice of the Architectural Actions (AA), are clearly established. When the question comes to how to build a passive house in warmer, hot, and very hot climates, the strategies arepoor and often results of a combination of western strategies with a local relook. From several visits in MiddleEast countries, Saudi Arabia, UAE, Oman, Palestine, Qatar, we concluded that the strategy for low consumption houses is not established yet and poorly grasped. The lack of training on low energy consumption in hot climate and the low price of energy, force designers and owners to rely on over usage of air-conditioning systems as measures to catch up on poor bioclimatic design. This method proposes a new approach on bioclimatic designfor hot climates from an architect point of view. It is based on a Cooling Degrees Days (CDD) and Heating Degrees Days (HDD) approach, a state of art of contemporary architecture and professional experience. Localclimates are classified according to the energy-hunger of six situations of the exterior temperature during night/day : cold/cold, cold/cool, cool/warm, cold/hot, cool/hot, and hot/hot as CDD and HDD of the twelve month ofthe year. A group of days on one of those situations will be called “climatic season”. In parallel we will create two main “climatic situations”: people keep the house closed to the exterior or opened to the exterior. We will associate passive strategies to these two differents ways to live in the house: “cold” and “hot” to a closed houseand “cool” and “warm” to a house opened up to the exterior. This method allows classifying any climate in theworld under these six climatic seasons. Our climate classification can now be associated to different strategies that we will call “architectural actions” as house is closed or opened. We could already start to design a house from here, but to better understand the influence of each action we have created an Energy+ model to analyze individually the effect of a single AA. The performance of each action is evaluated under the situations of six representative journeys as well as a year round on a very hot city: Dubai. The result of the effect good or badof action during each different season situation allows us to create the best combination of AA that are best fora year round climate resulting of the combination of several climatic seasons. This low-tech method will help usto find the common features of the houses of different hot climates of a big region and find the best typology. We have carried in parallel a cost study of the base house and the financial incidence of each single action to evaluate also the payback period by action.
9

Energy-Efficient Turbo Decoder for 3G Wireless Terminals

Al-Mohandes, Ibrahim January 2005 (has links)
Since its introduction in 1993, the turbo coding error-correction technique has generated a tremendous interest due to its near Shannon-limit performance. Two key innovations of turbo codes are parallel concatenated encoding and iterative decoding. In its IMT-2000 initiative, the International Telecommunication Union (ITU) adopted turbo coding as a channel coding standard for Third-Generation (3G) wireless high-speed (up to 2 Mbps) data services (cdma2000 in North America and W-CDMA in Japan and Europe). For battery-powered hand-held wireless terminals, energy consumption is a major concern. In this thesis, a new design for an energy-efficient turbo decoder that is suitable for 3G wireless high-speed data terminals is proposed. The Log-MAP decoding algorithm is selected for implementation of the constituent Soft-Input/Soft-Output (SISO) decoder; the algorithm is approximated by a fixed-point representation that achieves the best performance/complexity tradeoff. To attain energy reduction, a two-stage design approach is adopted. First, a novel dynamic-iterative technique that is appropriate for both good and poor channel conditions is proposed, and then applied to reduce energy consumption of the turbo decoder. Second, a combination of architectural-level techniques is applied to obtain further energy reduction; these techniques also enhance throughput of the turbo decoder and are area-efficient. The turbo decoder design is coded in the VHDL hardware description language, and then synthesized and mapped to a 0. 18<i>&mu;</i>m CMOS technology using the standard-cell approach. The designed turbo decoder has a maximum data rate of 5 Mb/s (at an upper limit of five iterations) and is 3G-compatible. Results show that the adopted two-stage design approach reduces energy consumption of the turbo decoder by about 65%. A prototype for the new turbo codec (encoder/decoder) system is implemented on a Xilinx XC2V6000 FPGA chip; then the FPGA is tested using the CMC Rapid Prototyping Platform (RPP). The test proves correct functionality of the turbo codec implementation, and hence feasibility of the proposed turbo decoder design.
10

Energy-Efficient Turbo Decoder for 3G Wireless Terminals

Al-Mohandes, Ibrahim January 2005 (has links)
Since its introduction in 1993, the turbo coding error-correction technique has generated a tremendous interest due to its near Shannon-limit performance. Two key innovations of turbo codes are parallel concatenated encoding and iterative decoding. In its IMT-2000 initiative, the International Telecommunication Union (ITU) adopted turbo coding as a channel coding standard for Third-Generation (3G) wireless high-speed (up to 2 Mbps) data services (cdma2000 in North America and W-CDMA in Japan and Europe). For battery-powered hand-held wireless terminals, energy consumption is a major concern. In this thesis, a new design for an energy-efficient turbo decoder that is suitable for 3G wireless high-speed data terminals is proposed. The Log-MAP decoding algorithm is selected for implementation of the constituent Soft-Input/Soft-Output (SISO) decoder; the algorithm is approximated by a fixed-point representation that achieves the best performance/complexity tradeoff. To attain energy reduction, a two-stage design approach is adopted. First, a novel dynamic-iterative technique that is appropriate for both good and poor channel conditions is proposed, and then applied to reduce energy consumption of the turbo decoder. Second, a combination of architectural-level techniques is applied to obtain further energy reduction; these techniques also enhance throughput of the turbo decoder and are area-efficient. The turbo decoder design is coded in the VHDL hardware description language, and then synthesized and mapped to a 0. 18<i>&mu;</i>m CMOS technology using the standard-cell approach. The designed turbo decoder has a maximum data rate of 5 Mb/s (at an upper limit of five iterations) and is 3G-compatible. Results show that the adopted two-stage design approach reduces energy consumption of the turbo decoder by about 65%. A prototype for the new turbo codec (encoder/decoder) system is implemented on a Xilinx XC2V6000 FPGA chip; then the FPGA is tested using the CMC Rapid Prototyping Platform (RPP). The test proves correct functionality of the turbo codec implementation, and hence feasibility of the proposed turbo decoder design.

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