Turbo Decoding
Mostrando 1-10 de 10 artigos, teses e dissertações.
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1. Grafos-fatores e decodificação iterativa : novas aplicações / Factor graphs and iterative decoding : new developments
Esta tese aborda métodos de estimação probabilística em sistemas de comunicações usando a teoria de grafos-fatores e seu algoritmo genérico soma-produto. Estas ferramentas são atualmente reconhecidas como um ambiente ideal para derivar vários esquemas de decodificação/ estimação, e também integrar modelos de componentes típicos num sistema de
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 25/03/2010
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2. Iterative decoding of q-ary turbo-product codes in FFH-CDMA systems / Decodificação iterativa de codigos turbo-produto q-arios em um Canal FFH-CDMA
This work presents a study of q-ary turbo decoding applied to FFH-CDMA systems. To attain the main objective of this dissertation, an algorithm to implement the q-ary soft decoding was designed. Specifically, an adaptation of the Chase decoding method was proposed to comply with q-ary symbols requirements. The proposal of iterative (turbo) decoding makes pos
Publicado em: 2007
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3. New proposals for optmization of digital TV receivers based on OFDM in regional single frequency network environments / Novas propostas para otimização de receptores de TV digital baseados em OFDM em ambientes de redes de frequencia unica regionais
This thesis deals with the optimization of Digital TV receivers based on OFDM, with performance evaluation in regional single frequency networks (SFN). Such environment facilitates the channel distribution, however its characteristics degrade the receiver operation. Initially, projects of loop canceller filters in relay stations are treated, and they are nec
Publicado em: 2007
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4. Projeto de EntrelaÃadores para cÃdigos turbo
Interleavers perform a central role in the near channel capacity performance of turbo codes. Besides been introduced as simple random permutations, nowadays there are several classes of interleavers like s-random, DRP, polynomial, and quasi-cyclic that provide a better performance for turbo codes in an AWGN channel and/or are simpler to store. This work has
Publicado em: 2006
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5. Distributed coding turbo codes and second generation wavelets / Codificação distribuida de video digital utilizando codigos turbo e Waveletes de segunda geração
Distributed video coding is a new paradigm for video compression in opposition over the existing video coding standards like MPEG-x and H.26x families. These codecs make use of motion estimation algorithms, the main part of the compression process of the video signal. Hence, the compression process demands a high computational cost and high performance of th
Publicado em: 2006
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6. Um Esquema de Equalização Turbo Aplicando Decodificação Turbo de Códigos Produto de Paridade Simples Multidimensionais / Turbo Equalization Using Single Parity Check Codes / Um Esquema de Equalização Turbo Aplicando Decodificação Turbo de Códigos Produto de Paridade Simples Multidimensionais / Turbo Equalization Using Single Parity Check Codes
Combining existing blocks in a novel way, a turbo equalizer structure is proposed here for fixed multipath channels. The existing combined turbo equalization with turbo decoding make a complete turbo iteration in the turbo decoder at each turbo equalizer iteration. The proposed scheme here uses a single component decoder of a block turbo code. At each iterat
Publicado em: 2005
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7. CodificaÃÃo iterativa para o canal adtivo com dois usuÃrios binÃrios
This thesis is concerned with an investigation of iterative coding schemes for the two-user binary adder channel (2-BAC). A coding scheme is introduced for the 2-BAC using a single convolutional code which permits efficient decoding. The constructed two-user trellis codes have a significant practical advantage because iterative decoding techniques used in th
Publicado em: 2005
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8. Tecnicas autodidatas e soluções de baixa complexidade para equalização e estimação turbo
This work concerns the use of iterative receivers, which jointly perform equalization, decoding and channel estimation, to mitigate the impairments introduced by the transmission medium into the transmitted signal. First, we make a comparative study of exponential-and reduced-complexity turbo equalizers and establish the advantages and the limitations of eac
Publicado em: 2005
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9. Códigos de Bloco com Decodificação Turbo Adaptados às Especificações do Padrão DVB-RCT / Códigos de Bloco com Decodificação Turbo Adaptados às Especificações do Padrão DVB-RCT
Product codes formed by serial concatenation of single parity check component codes are used in this thesis to fulfill the requirements of coding rate and block length expressed by the standard known as DVB-RCT (Digital Video Broadcasting - Return Channel Terrestrial). This standard describes the parameters of the physical layer for a digital TV wireless ret
Publicado em: 2004
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10. Uma rede de codificação/decodificação para canais não-coerentes
Due to the extraordinary results, widely mentioned in the literature, attained with turbo decoding, new research lines have been suggested and followed, trying to apply these contributions in new decoding sceneries. Among the existing applications, the concept of decoding networks, reception systems using what is known as turbo principIe or iterative process
Publicado em: 2001