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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.
61

Quaternary CLB a falul tolerant quaternary FPGA

Rhod, Eduardo Luis January 2012 (has links)
A diminuição no tamanho dos transistores vem aumentando cada vez mais o número de funções que os dispositivos eletrônicos podem realizar. Apesar da diminuição do tamanho mínimo dos transistores, a velocidade máxima dos circuitos não consegue seguir a mesma taxa de aumento. Um dos grandes culpados apontados pelos pesquisadores são as interconexões entre os transistores e também entre os componentes. O aumento no número de interconexões dos circuitos traz consigo um significativo aumento do cosumo de energia, aumento do atraso de propagação dos sinais, além de um aumento da complexidade e custo do projeto dos circuitos integrados. Como uma possível solução a este problema é proposta a utilização de lógica multivalorada, mais especificamente, a lógica quaternária. Os dispositivos FPGAs são caracterizados principalmente pela grande flexibilidade que oferecem aos projetistas de sistemas digitais. Entretanto, com o avanço nas tecnologias de fabricação de circuitos integrados e diminuição das dimensões de fabricação, os problemas relacionados ao grande número de interconexões são uma preocupação para as próximas tecnologias de FPGAs. As tecnologias menores que 90nm possuem um grande aumento na taxa de erros dos circuitos, na lógica combinacional e sequencial. Apesar de algumas potenciais soluções começara a ser investigadas pela comunidade, a busca por circuitos tolerantes a erros induzidos por radiação, sem penalidades no desempenho, área ou potência, ainda é um assunto de pesquisa em aberto. Este trabalho propõe o uso de circuitos quaternários com modificações para tolerar falhas provenientes de eventos transientes. Como principal contribuição deste trabalho destaca-se o desenvolvimento de uma CLB (do inglês Configurable Logic Block) quaternária capaz de suportar eventos transientes e, na possibilidade de um erro, evitá-lo ou corrigi-lo. / The decrease in transistor size is increasing the number of functions that can be performed by the electronic devices. Despite this reduction in the transistors minimum size, the circuit’s speed does not follow the same rate. One of the major reasons pointed out by researchers are the interconnections between the transistors and between the components. The increase in the number of circuit interconnections brings a significant increase in energy consumption, propagation delay of signals, and an increase in the complexity and cost of new technologies IC designs. As a possible solution to this problem the use of multivalued logic is being proposed, more specifically, the quaternary logic. FPGA devices are characterized mainly by offering greater flexibility to designers of digital systems. However, with the advance in IC manufacturing technologies and the reduced size of the minimum fabricated dimensions, the problems related to the large number of interconnections are a concern for future technologies of FPGAs. The sub 90nm technologies have a large increase in the error rate of its functions for the combinational and sequential logic. Although potential solutions are being investigated by the community, the search for circuits tolerant to radiation induced errors, without performance, area, or power penalties, is still an open research issue. This work proposes the use of quaternary circuits with modifications to tolerate faults from transient events. The main contribution of this work is the development of a quaternary CLB (Configurable Logic Block) able to withstand transient events and the occurrence of soft errors.
62

Variation Aware Placement for Efficient Key Generation using Physically Unclonable Functions in Reconfigurable Systems

Vyas, Shrikant S 07 November 2016 (has links)
With the importance of data security at its peak today, many reconfigurable systems are used to provide security. This protection is often provided by FPGA-based encrypt/decrypt cores secured with secret keys. Physical unclonable functions (PUFs) use random manufacturing variations to generate outputs that can be used in keys. These outputs are specific to a chip and can be used to create device-tied secret keys. Due to reliability issues with PUFs, key generation with PUFs typically requires error correction techniques. This can result in substantial hardware costs. Thus, the total cost of a $n$-bit key far exceeds just the cost of producing $n$ bits of PUF output. To tackle this problem, we propose the use of variation aware intra-FPGA PUF placement to reduce the area cost of PUF-based keys on FPGAs. We show that placing PUF instances according to the random variations of each chip instance reduces the bit error rate of the PUFs and the overall resources required to generate the key. Our approach has been demonstrated on a Xilinx Zynq-7000 programmable SoC using FPGA specific PUFs with code-offset error correction based on BCH codes. The approach is applicable to any PUF-based system implemented in reconfigurable logic. To evaluate our approach, we first analyze the key metrics of a PUF - reliability and uniqueness. Reliability is related to bit error rate, an important parameter with respect to error correction. In order to generate reliable results from the PUFs, a total of four ZedBoards containing FPGAs are used in our approach. We quantify the effectiveness of our approach by implementing the same key generation scheme using variation-aware and default placement, and show the resources saved by our approach.
63

A Modular Platform for Adaptive Heterogeneous Many-Core Architectures

Atef, Ahmed Kamaleldin 18 December 2023 (has links)
Multi-/many-core heterogeneous architectures are shaping current and upcoming generations of compute-centric platforms which are widely used starting from mobile and wearable devices to high-performance cloud computing servers. Heterogeneous many-core architectures sought to achieve an order of magnitude higher energy efficiency as well as computing performance scaling by replacing homogeneous and power-hungry general-purpose processors with multiple heterogeneous compute units supporting multiple core types and domain-specific accelerators. Drifting from homogeneous architectures to complex heterogeneous systems is heavily adopted by chip designers and the silicon industry for more than a decade. Recent silicon chips are based on a heterogeneous SoC which combines a scalable number of heterogeneous processing units from different types (e.g. CPU, GPU, custom accelerator). This shifting in computing paradigm is associated with several system-level design challenges related to the integration and communication between a highly scalable number of heterogeneous compute units as well as SoC peripherals and storage units. Moreover, the increasing design complexities make the production of heterogeneous SoC chips a monopoly for only big market players due to the increasing development and design costs. Accordingly, recent initiatives towards agile hardware development open-source tools and microarchitecture aim to democratize silicon chip production for academic and commercial usage. Agile hardware development aims to reduce development costs by providing an ecosystem for open-source hardware microarchitectures and hardware design processes. Therefore, heterogeneous many-core development and customization will be relatively less complex and less time-consuming than conventional design process methods. In order to provide a modular and agile many-core development approach, this dissertation proposes a development platform for heterogeneous and self-adaptive many-core architectures consisting of a scalable number of heterogeneous tiles that maintain design regularity features while supporting heterogeneity. The proposed platform hides the integration complexities by supporting modular tile architectures for general-purpose processing cores supporting multi-instruction set architectures (multi-ISAs) and custom hardware accelerators. By leveraging field-programmable-gate-arrays (FPGAs), the self-adaptive feature of the many-core platform can be achieved by using dynamic and partial reconfiguration (DPR) techniques. This dissertation realizes the proposed modular and adaptive heterogeneous many-core platform through three main contributions. The first contribution proposes and realizes a many-core architecture for heterogeneous ISAs. It provides a modular and reusable tilebased architecture for several heterogeneous ISAs based on open-source RISC-V ISA. The modular tile-based architecture features a configurable number of processing cores with different RISC-V ISAs and different memory hierarchies. To increase the level of heterogeneity to support the integration of custom hardware accelerators, a novel hybrid memory/accelerator tile architecture is developed and realized as the second contribution. The hybrid tile is a modular and reusable tile that can be configured at run-time to operate as a scratchpad shared memory between compute tiles or as an accelerator tile hosting a local hardware accelerator logic. The hybrid tile is designed and implemented to be seamlessly integrated into the proposed tile-based platform. The third contribution deals with the self-adaptation features by providing a reconfiguration management approach to internally control the DPR process through processing cores (RISC-V based). The internal reconfiguration process relies on a novel DPR controller targeting FPGA design flow for RISC-V-based SoC to change the types and functionalities of compute tiles at run-time.
64

Cost Beneficial Solution for High Rate Data Processing

Mirchandani, Chandru, Fisher, David, Ghuman, Parminder 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / GSFC in keeping with the tenets of NASA has been aggressively investigating new technologies for spacecraft and ground communications and processing. The application of these technologies, together with standardized telemetry formats, make it possible to build systems that provide high-performance at low cost in a short development cycle. The High Rate Telemetry Acquisition System (HRTAS) Prototype is one such effort that has validated Goddard's push towards faster, better and cheaper. The HRTAS system architecture is based on the Peripheral Component Interconnect (PCI) bus and VLSI Application-Specific Integrated Circuits (ASICs). These ASICs perform frame synchronization, bit-transition density decoding, cyclic redundancy code (CRC) error checking, Reed-Solomon error detection/correction, data unit sorting, packet extraction, annotation and other service processing. This processing in performed at rates of up to and greater than 150 Mbps sustained using a high-end performance workstation running standard UNIX O/S, (DEC 4100 with DEC UNIX or better). ASICs are also used for the digital reception of Intermediate Frequency (IF) telemetry as well as the spacecraft command interface for commands and data simulations. To improve the efficiency of the back-end processing, the level zero processing sorting element is being developed. This will provide a complete hardware solution to extracting and sorting source data units and making these available in separate files on a remote disk system. Research is on going to extend this development to higher levels of the science data processing pipeline. The fact that level 1 and higher processing is instrument dependent; an acceleration approach utilizing ASICs is not feasible. The advent of field programmable gate array (FPGA) based computing, referred to as adaptive or reconfigurable computing, provides a processing performance close to ASIC levels while maintaining much of the programmability of traditional microprocessor based systems. This adaptive computing paradigm has been successfully demonstrated and its cost performance validated, to make it a viable technology for the level one and higher processing element for the HRTAS. Higher levels of processing are defined as the extraction of useful information from source telemetry data. This information has to be made available to the science data user in a very short period of time. This paper will describe this low cost solution for high rate data processing at level one and higher processing levels. The paper will further discuss the cost-benefit of this technology in terms of cost, schedule, reliability and performance.
65

Towards the development of a reliable reconfigurable real-time operating system on FPGAs

Hong, Chuan January 2013 (has links)
In the last two decades, Field Programmable Gate Arrays (FPGAs) have been rapidly developed from simple “glue-logic” to a powerful platform capable of implementing a System on Chip (SoC). Modern FPGAs achieve not only the high performance compared with General Purpose Processors (GPPs), thanks to hardware parallelism and dedication, but also better programming flexibility, in comparison to Application Specific Integrated Circuits (ASICs). Moreover, the hardware programming flexibility of FPGAs is further harnessed for both performance and manipulability, which makes Dynamic Partial Reconfiguration (DPR) possible. DPR allows a part or parts of a circuit to be reconfigured at run-time, without interrupting the rest of the chip’s operation. As a result, hardware resources can be more efficiently exploited since the chip resources can be reused by swapping in or out hardware tasks to or from the chip in a time-multiplexed fashion. In addition, DPR improves fault tolerance against transient errors and permanent damage, such as Single Event Upsets (SEUs) can be mitigated by reconfiguring the FPGA to avoid error accumulation. Furthermore, power and heat can be reduced by removing finished or idle tasks from the chip. For all these reasons above, DPR has significantly promoted Reconfigurable Computing (RC) and has become a very hot topic. However, since hardware integration is increasing at an exponential rate, and applications are becoming more complex with the growth of user demands, highlevel application design and low-level hardware implementation are increasingly separated and layered. As a consequence, users can obtain little advantage from DPR without the support of system-level middleware. To bridge the gap between the high-level application and the low-level hardware implementation, this thesis presents the important contributions towards a Reliable, Reconfigurable and Real-Time Operating System (R3TOS), which facilitates the user exploitation of DPR from the application level, by managing the complex hardware in the background. In R3TOS, hardware tasks behave just like software tasks, which can be created, scheduled, and mapped to different computing resources on the fly. The novel contributions of this work are: 1) a novel implementation of an efficient task scheduler and allocator; 2) implementation of a novel real-time scheduling algorithm (FAEDF) and two efficacious allocating algorithms (EAC and EVC), which schedule tasks in real-time and circumvent emerging faults while maintaining more compact empty areas. 3) Design and implementation of a faulttolerant microprocessor by harnessing the existing FPGA resources, such as Error Correction Code (ECC) and configuration primitives. 4) A novel symmetric multiprocessing (SMP)-based architectures that supports shared memory programing interface. 5) Two demonstrations of the integrated system, including a) the K-Nearest Neighbour classifier, which is a non-parametric classification algorithm widely used in various fields of data mining; and b) pairwise sequence alignment, namely the Smith Waterman algorithm, used for identifying similarities between two biological sequences. R3TOS gives considerably higher flexibility to support scalable multi-user, multitasking applications, whereby resources can be dynamically managed in respect of user requirements and hardware availability. Benefiting from this, not only the hardware resources can be more efficiently used, but also the system performance can be significantly increased. Results show that the scheduling and allocating efficiencies have been improved up to 2x, and the overall system performance is further improved by ~2.5x. Future work includes the development of Network on Chip (NoC), which is expected to further increase the communication throughput; as well as the standardization and automation of our system design, which will be carried out in line with the enablement of other high-level synthesis tools, to allow application developers to benefit from the system in a more efficient manner.
66

Ferramentas e metodologias de desenvolvimento para sistemas parcialmente reconfiguráveis. / Development tools and methodologies for partial reconfigurable systems.

Valiante Filho, Filippo 19 May 2008 (has links)
Alguns tipos de FPGA (Field Programmable Gate Array) possuem a capacidade de serem reconfigurados parcialmente em tempo de execução formando um Sistema Parcialmente Reconfigurável (SPR), cuja utilização traz diversas vantagens dentre as quais a redução de custos. A maior utilização de SPRs enfrenta, como um dos fatores limitantes, a dificuldade de acesso e de utilização de ferramentas de desenvolvimento apropriadas. Este trabalho aborda os SPRs, suas aplicações e uma análise das ferramentas de desenvolvimento existentes. posteriormente dedica-se ao aperfeiçoamento de uma dessas ferramentas, o PARBIT, com o desenvolvimento de uma interface gráfica de usuário (GUI, -- Graphical User Interface) e a atualização de sua metodologia de desenvolvimento. As metodologias de projeto suportadas pelo fabricante do FPGA também são apresentadas. As metodologias são validadas através do projeto de um SPR. / Some types of FPGA (Field Programmable Gate Array) can be partially reconfigured during run-time forming a Partial Reconfigurable System (PRS). The use of PRSs brings several advantages like cost reduction. A larger use of PRSs faces a limiting factor: the difficult to access and use appropriate development tools. This work shows the PRSs, its applications and an analysis of the existing development tools. Later, it dedicates to the improvement of one of these tools, the PARBIT, developing a graphical user interface (GUI) and updating its project methodology. The project methodologies supported by the manufacturer of the FPGA are also presented. The methodologies are validated through the design of a PRS.
67

Análise do uso de redundância em circuitos gerados por síntese de alto nível para FPGA programado por SRAM sob falhas transientes

Santos, André Flores dos January 2017 (has links)
Este trabalho consiste no estudo e análise da suscetibilidade a efeitos da radiação em projetos de circuitos gerados por ferramenta de Síntese de Alto Nível para FPGAs (Field Programmable Gate Array), ou seja, circuitos programáveis e sistemas em chip, do inglês System-on-Chip (SOC). Através de um injetor de falhas por emulação usando o ICAP (Internal Configuration Access Port) localizado dentro do FPGA é possível injetar falhas simples ou acumuladas do tipo SEU (Single Event Upset), definidas como perturbações que podem afetar o funcionamento correto do dispositivo através da inversão de um bit por uma partícula carregada. SEU está dentro da classificação de SEEs (Single Event Effects), efeitos transitórios em tradução livre, podem ocorrer devido a penetração de partículas de alta energia do espaço e do sol (raios cósmicos e solares) na atmosfera da Terra que colidem com átomos de nitrogênio e oxigênio resultando na produção de partículas carregadas, na grande maioria nêutrons. Dentro deste contexto além de analisar a suscetibilidade de projetos gerados por ferramenta de Síntese de Alto Nível, torna-se relevante o estudo de técnicas de redundância como TMR (Triple Modular Redundance) para detecção, correção de erros e comparação com projetos desprotegidos verificando a confiabilidade. Os resultados mostram que no modo de injeção de falhas simples os projetos com redundância TMR demonstram ser efetivos. Na injeção de falhas acumuladas o projeto com múltiplos canais apresentou melhor confiabilidade do que o projeto desprotegido e com redundância de canal simples, tolerando um maior número de falhas antes de ter seu funcionamento comprometido. / This work consists of the study and analysis of the susceptibility to effects of radiation in circuits projects generated by High Level Synthesis tool for FPGAs Field Programmable Gate Array (FPGAs), that is, system-on-chip (SOC). Through an emulation fault injector using ICAP (Internal Configuration Access Port), located inside the FPGA, it is possible to inject single or accumulated failures of the type SEU (Single Event Upset), defined as disturbances that can affect the correct functioning of the device through the inversion of a bit by a charged particle. SEU is within the classification of SEEs (Single Event Effects), can occur due to the penetration of high energy particles from space and from the sun (cosmic and solar rays) in the Earth's atmosphere that collide with atoms of nitrogen and oxygen resulting in the production of charged particles, most of them neutrons. In this context, in addition to analyzing the susceptibility of projects generated by a High Level Synthesis tool, it becomes relevant to study redundancy techniques such as TMR (Triple Modular Redundancy) for detection, correction of errors and comparison with unprotected projects verifying the reliability. The results show that in the simple fault injection mode TMR redundant projects prove to be effective. In the case of accumulated fault injection, the multichannel design presented better reliability than the unprotected design and with single channel redundancy, tolerating a greater number of failures before its operation was compromised.
68

Projeto e implementação em DSP de sistema de comunicação multiportadora baseado no padrão G.fast

ALMEIDA, Igor Mesquita de 30 August 2013 (has links)
Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2014-01-13T19:50:22Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProjetoImplementacaoDSP.pdf: 2021380 bytes, checksum: 2d32d5c81f5dd54fd2354280c6ac7e8c (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2014-01-17T13:31:11Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProjetoImplementacaoDSP.pdf: 2021380 bytes, checksum: 2d32d5c81f5dd54fd2354280c6ac7e8c (MD5) / Made available in DSpace on 2014-01-17T13:31:11Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ProjetoImplementacaoDSP.pdf: 2021380 bytes, checksum: 2d32d5c81f5dd54fd2354280c6ac7e8c (MD5) Previous issue date: 2013 / As redes de acesso usando cabos de cobre atualmente utilizam bandas de frequência até 30 MHz, especificada no padrão VDSL2. À medida que arquiteturas híbridas de fibra e cobre se tornam mais proeminentes na indústria e academia, torna-se possível utilizar cabos metálicos mais curtos (i.e. até 250 metros) conectando o último ponto de distribuição aos usuários, de modo que frequências mais altas podem ser exploradas para se alcançar taxas de transmissão de dados de 500 Mbps ou mais, como é o caso do padrão G.fast atualmente em desenvolvimento no ITU-T. Nesse trabalho, um simulador no domínio do tempo foi desenvolvido para avaliar a capacidade do sistema G.fast com diferentes tamanhos de extensão cíclica e diferentes topologias de rede especificadas pelo ITU-T. Os resultados das simulações mostram que sistemas G.fast são robustos a bridged taps e capazes de atingir altas taxas de dados para todas as topologias simuladas, provendo suporte à próxima geração de serviços de banda larga. Além disso, esse trabalho descreve o progresso da implementação de um protótipo de modem baseado no padrão G.fast em um ambiente híbrido de DSP multicore e FPGA utilizando kits de avaliação adquiridos pela UFPA. Arquiteturas, protocolos de comunicação e benchmarks são apresentados e avaliados para se chegar à conclusão de que tal protótipo é factível e fornece suporte flexível a várias linhas de pesquisa em banda larga da próxima geração. / The evolving broadband access systems using copper networks are currently deployed in a frequency band that goes up to 30 MHz, as specified in VDSL2. As hybrid fiber-copper architectures become more important in the industry and academia, using shorter loop lengths (i.e. up to 250 meters) from the last distribution point to users enables adopting even higher frequencies to achieve very high data rates of 500 Mbps and beyond, as is the case with the G.fast standard under development by ITU-T. In this work, a time-domain simulator has been developed to evaluate G.fast system performance with different cyclic extension lengths and different reference loop topologies specified by ITU-T. The simulation results show that G.fast systems are robust to bridged taps and capable of providing very high data rates for all simulated loop topologies to support next generation ultra high speed broadband services. Furthermore, this work describes an ongoing effort to implement a G.fast-based modem protototype in a hybrid multicore DSP and FPGA environment using readily-available evaluation kits purchased by UFPA. Architecture plans, communication protocols and benchmarks are presented and evaluated to conclude that such a prototype is both feasible and flexible to support several avenues of research in next generation broadband.
69

FPGA-based testbed for fronthaul signal compression: implementation and validation

FORTUNA, Joary Paulo Wanzeller 24 March 2017 (has links)
Submitted by Hellen Luz (hellencrisluz@gmail.com) on 2017-07-06T15:54:25Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_FPGABasedTestbed.pdf: 3904128 bytes, checksum: 2ef471e85263c54c068b8c792f35c257 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-08-18T13:44:42Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_FPGABasedTestbed.pdf: 3904128 bytes, checksum: 2ef471e85263c54c068b8c792f35c257 (MD5) / Made available in DSpace on 2017-08-18T13:44:42Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_FPGABasedTestbed.pdf: 3904128 bytes, checksum: 2ef471e85263c54c068b8c792f35c257 (MD5) Previous issue date: 2017-03-24 / FADESP - Fundação de Amparo e Desenvolvimento da Pesquisa / Nos últimos anos o mundo tem visto uma demanda crescente por serviços móveis de alta capacidade e baixo custo, isto tem forçado as tecnologias da rede de acesso móvel a serem repensadas. Entre as diferentes arquiteturas propostas na literatura, uma que ganhou bastante atenção é a centralização dos recursos da rede. Essa estratégia propõe compartilhar os recursos da rede através da centralização do processamento em banda-base, e como resultado reduzir o custo da rede. Apesar da centralização trazer vários benefícios, ela também aumenta a distancia entre o ponto onde os sinais são capturadas e o ponto onde são processados, o link que conecta esses dois pontos é chamado de fronthaul. Nesse cenário, as tecnologias de fronthaul existentes não são apropriadas para os requisitos de flexibilidade e custo esperados para a próxima geração de redes fronthaul, devido principalmente ao uso de links óticos dedicados. Uma solução para esses problemas é a utilização de Ethernet para transportar o trafego fronthaul, devido a sua onipresença, flexibilidade e baixo custo. Neste trabalho um testbed para fronthaul baseado em Ethernet ´e apresentado, juntamente com os detalhes de implementação e resultados de validação. Além disso, motivado pela limitação em banda existente no Ethernet, este trabalho apresenta a implementação em VHDL de um algoritmo de compressão de sinais LTE, avaliado em uma rede Ethernet real através do testbed. Os resultados obtidos indicam que é possível utilizar a infra-estruturar provida pela rede Ethernet no transporte de fronthaul. Por outro lado é necessário reduzir os requisitos exigidos pelo tráfego fronthaul. Através, por exemplo, da aplicação da compressão de sinais e de técnicas de sincronismo. / In recent years the world has seen an increasing demand for mobile services with high capacity and low cost. Such requirements forced the radio access technologies to be rethought. Among the different architectures proposed in literature, one that has got a lot of attention was the Centralized Radio Access Network (C-RAN). This strategy proposes to share the network resources through the centralization of the base-band processing and, as a result, reduce the network cost. Even though the centralization can bring several benefits, it also increases the distance between the point where the signal is captured and the point where it is processed. The link connecting both points is called fronthaul. In this scenario, the existing fronthaul technologies do not fit in the flexibility and cost requisites expected for the next generation mobile network, mainly due to the usage of dedicated optical links. One solution to these problems is the usage of Ethernet to transport fronthaul data, due to its ubiquitous presence, flexibility and low cost. In this work, a testbed for fronthaul based on Ethernet is presented, along with the implementation details and validation results. Also motivated by the Ethernet’s bandwidth limitation, this work presents the VHDL implementation of a compression technique for LTE signals, evaluated in real transport conditions with the testbed. The obtained results indicate that it is possible to utilize the Ethernet network infrastructure for fronthaul transport. Although, it is necessary to reduce the requirements of Fronthaul stream through, for example, the application of signal compression techniques and synchronization methods.
70

MARTE based model driven design methodology for targeting dynamically reconfigurable FPGA based SoCs

Quadri, Imran Rafiq 20 April 2010 (has links) (PDF)
Les travaux présentés dans cette thèse sont effectuées dans le cadre des Systèmes sur puce (SoC, Systemon Chip) et la conception de systèmes embarqués en temps réel, notamment dédiés au domaine de la reconfiguration dynamique, liés à ces systèmes complexes. Dans ce travail, nous présentons un nouveau flot de conception basé sur l'Ingénierie Dirigée par les Modèles (IDM/MDE) et le profilMARTE pour la conception conjointe du SoC, la spécification et la mise en oeuvre de ces systèmes sur puce reconfigurables, afin d'élever les niveaux d'abstraction et de réduire la complexité du système. La première contribution relative à cette thèse est l'identification des parties de systèmes sur puce reconfigurable dynamiquement qui peuvent être modélisées au niveau d'abstraction élevé. Cette thèse adapte une approche dirigée par l'application et cible les modèles d'application de haut niveau pour être traités comme des régions dynamiques des SoCs reconfigurables. Nous proposons aussi des modèles de contrôle générique pour la gestion de ces régions au cours de l'exécution en temps réel. Bien que cette sémantique puisse être introduite à différents niveaux d'abstraction d'un environnent pour la conception conjointe du SoC, nous insistons tout particulièrement sur sa fusion au niveau du déploiement, qui relie la propriété intellectuelle avec les éléments modélisés à haut niveau de conception. En outre, ces concepts ont été intégrés dans le méta-modèleMARTE et le profil correspondant afin de fournir une extension adéquate pour exprimer les caractéristiques de reconfiguration à la modélisation de haut niveau. La seconde contribution est la proposition d'un méta-modèle intermédiaire, qui isole les concepts présents au niveau transfert de registre (RTL-Register Transfer Level). Ce méta-modèle intègre les concepts chargés de l'exécution matérielle des applications modélisées, tout en enrichissant la sémantique de contrôle, provoquant la création d'un accélérateur matériel reconfigurable dynamiquement avec plusieurs implémentations disponibles. Enfin, en utilisant les transformations de modèlesMDE et les principes correspondants, nous sommes en mesure de générer des codeHDL équivalents à différentes implémentations de l'accélérateur reconfigurable ainsi que différents codes source en langage C/C++ liés au contrôleur de reconfiguration, qui est finalement responsable de la commutation entre les différentes mplémentations. Enfin, notre flot de conception a été vérifié avec succès dans une étude de cas liée à un système anti-radar de détection de collision. Une composante clé intégrante de ce système a été modélisée en utilisant les spécifications MARTE étendu et le code généré a été utilisé dans la conception et la mise en oeuvre d'un SoC sur un FPGA reconfigurable dynamiquement.

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