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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.
51

Reliability-based coded modulation for low-density parity-check codes /

Maddock, Robert D., January 1900 (has links)
Thesis (M. App. Sc.)--Carleton University, 2004. / Includes bibliographical references (p. 82-85). Also available in electronic format on the Internet.
52

Efficient simulation of space-time coded and turbo coded systems

Nguyen, Kim Chi. January 2007 (has links)
Thesis (Ph.D.)--University of Western Sydney, 2007. / A thesis submitted to the University of Western Sydney, College of Health and Science, School of Engineering in fulfilment of the requirements for the degree of Doctor of Philosophy in Engineering. Includes bibliographical references.
53

Computation of initial state for tail-biting trellis /

Chen, Yiqi. January 2005 (has links)
Thesis (M.S)--Ohio University, June, 2005. / Includes bibliographical references (p. 55-56)
54

Computation of initial state for tail-biting trellis

Chen, Yiqi. January 2005 (has links)
Thesis (M.S)--Ohio University, June, 2005. / Title from PDF t.p. Includes bibliographical references (p. 55-56)
55

[en] SIMULATION TRELLIS CODES WITH MULTI-DIMENSIONAL MODULATION FOR THE TELEPHONE CHANNEL / [pt] SIMULAÇÃO DE CÓDIGOS EM TRELIÇA COM MODULAÇÕES MULTI-DIMENSIONAIS PARA CANAL TELEFÔNICO

RUBEN LEVCOVITZ 09 November 2006 (has links)
[pt] O presente trabalho analisa, através de simulação, o desempenho de códigos em treliça em canais telefônicos. Os esquemas simulados correspondem a modulação com constelação multi-dimensionais codificadas, otimizadas de forma integrada utilizando a regra de mapeamento por particionamento de conjuntos. Uma técnica iterativa, eficiente, para obtenção de estrutura do codificador/modulador proposta por Wei [13], é examinada. O desempenho de um código com constelação bidimensional recomendado pelo CCITT é comparado com o desempenho de um código quadridimensional obtido com o método de Wei. / [en] A computer simulation analysis of the performance of trellis codes on telephone channel is done in this thesis. The simulated schemmes use coded modulations with multi- dimensional signal sets jointly optimized under the rule of mapping by set partitioning. An efficient iterative technique to obtain the structure of the encoder/modulator proposed by Wei [13] is examined. The performance of the CCITT recommended code with bidimensional constelation is compared to the performance of a four-dimensional code obtained with the Wei method.
56

Sistema estrutural treliçado modular em madeira - SET 2M / Wooden modulated latticed structural system SET 2M

Decio Gonçalves 11 December 2007 (has links)
O presente Trabalho de Tese objetiva a concepção e o desenvolvimento de um sistema estrutural treliçado modular em madeira. Avalia o comportamento de alguns dos seus principais elementos constituintes, através de experimentos realizados em laboratório e apresenta provas com programas funcionais, tornando factível a implantação do artefato arquitetônico em terrenos difíceis com mínimo impacto ambiental. Compara de forma estimativa os custos dessa estrutura executada em madeira, concreto e aço. É permeado em sua primeira fase por um breve relato da Arquitetura Brasileira em madeira, do colonial ao contemporâneo e pela descrição sucinta das características da madeira, privilegiando sua capacidade portante e finalmente pela concepção e desenvolvimento do sistema estrutural em madeira, objeto desse trabalho, denominado Sistema estrutural treliçado modular em madeira SET 2M. Em sua segunda parte, procura-se dotar o sistema com provas de programas funcionais: três residências unifamiliares, uma multifamiliar e uma pousada. O sistema baliza-se no princípio que, para se pensar e construir uma edificação de boa qualidade com baixo custo de construção, deve-se introduzir altos níveis de racionalidade e criatividade na concepção do espaço e na sua construção. O SET 2M é caracterizado pela aplicação metodológica da sucessão e continuidade de eventos, assim como da coerência de decisões, em função de suas racionalidades de concepção e de construção, as quais objetivam organizar e prever diferentes operações em oficinas de marcenaria e serralharia em suas montagens no canteiro de obras. Essas montagens processam-se através da utilização de: 1) recursos simples, exigindo equipamentos e ferramentais disponibilizados correntemente no mercado na construção civil; 2) equipe composta por um número reduzido de pessoal; 3) prazo de execução exíguo, devido às suas características projetuais de concepção e de construção. A madeira se apresenta como um material atraente para essas concepções, pois equipara-se, em termos de custos, ao aço, material altamente empregado nos dias atuais e supera em muito o concreto protendido, material possível de execução quando pensado com as características específicas do SET 2M. Para a concepção e o desenvolvimento do SET 2M realizouse, no laboratório do LAME da FAUUSP, maquetes e protótipos de alguns dos mais significativos de seus elementos constituintes, que atestaram de forma bastante satisfatória o comportamento do sistema. A estrutura foi calculada no nível de desenvolvimento inicial, possibilitando, assim, sua estabilização geral. / The present Thesis aims the conception and the development of a wooden modulated latticed structural system. This work evaluates the behavior of some of its main constituent elements, through experiments carried through in laboratory, and presents tests with functional programs, becoming feasible the implantation of the architectural device in difficult lands with minimum environmental impact. It compares and esteems the costs of this structure executed in wood, concrete and steel. It is composed in its first phase by a brief story of the Brazilian Architecture in wood, from the colonial to the contemporary, a quick description of the characteristics of the wood, privileging its carrying capacity, and finally by the conception and development of the wooden structural system, the object of this work, called Wooden modulated latticed structural system SET 2M. In its second part, it looks to endow the system with tests in functional programs: three single residences, one familiar residence and a resort inn. The system is based in this principle: to think and to construct a building of good quality with low cost of construction, we must introduce high levels of rationality and creativity in the conception of the space and its construction. The SET 2M is characterized by a methodological application of the succession and continuity of events, as well as of the coherence of decisions, in function of its rationalities of conception and construction, which aim to organize and to foresee different operations in joineries, carpentries and locksmiths in its assemblies in the building. These assemblies are processed by the use of: 1) simple resources, demanding equipment and tools currently available in the market in the civil construction; 2) team composed by a reduced number of staff; 3) short stated period, due to its projected characteristics of conception and construction. Wood presents itself as an attractive material for these conceptions, because it compares in cost to the steel, highly used nowadays, and it surpasses the extended concrete, a possible material of execution when thought with the specific characteristics of SET 2M. For the conception and the development of the SET 2M, we built in the laboratory of the LAME of the FAUUSP mockups and prototypes of its expressive constituent elements, which certified satisfactorily the behavior of the system. The structure was calculated in the level of initial development, making possible, thus, its general stabilization.
57

Ternary coding and triangular modulation

Abdelaziz, Mahmoud Karem Mahmoud 16 August 2017 (has links)
Adaptive modulation is widely employed to improve spectral e ciency. To date, square signal constellations have been used for adaptive modulation. In this disser- tation, triangular constellations are considered for this purpose. Triangle quadrature amplitude modulation (TQAM) for both power-of-two and non-power-of-two mod- ulation orders is examined. A technique for TQAM mapping is presented which is better than existing approaches. A new type of TQAM called semi-regular TQAM (S-TQAM) is introduced. Bit error rate expressions for TQAM are derived, and the detection complexity of S-TQAM is compared with that of regular TQAM (R-TQAM) and irregular TQAM (I-TQAM). The performance of S-TQAM over additive white Gaussian noise and Rayleigh fading channels is compared with that of R-TQAM and I-TQAM. The construction of ternary convolutional codes (TCCs) for ternary phase shift keying (TPSK) modulation is considered. Tables of non-recursive non-systematic TCCs with maximum free distance are given for rates 1=2, 1=3 and 1=4. The conver- sion from binary data to ternary symbols is investigated. The performance of TCCs with binary to ternary conversion using TPSK is compared with the best BCCs using binary phase shift keying (BPSK). / Graduate
58

Distance-preserving mappings and trellis codes with permutation sequences

Swart, Theo G. 27 June 2008 (has links)
Our research is focused on mapping binary sequences to permutation sequences. It is established that an upper bound on the sum of the Hamming distance for all mappings exists, and this sum is used as a criterion to ascertain how good previously known mappings are. We further make use of permutation trellis codes to investigate the performance of certain permutation mappings in a power-line communications system, where background noise, narrow band noise and wide band noise are present. A new multilevel construction is presented next that maps binary sequences to permutation sequences, creating new mappings for which the sum of Hamming distances are greater than previous known mappings. It also proved that for certain lengths of sequences, the new construction can attain our new upper bound on the sum of Hamming distances. We further extend the multilevel construction by showing how it can be applied to other mappings, such as permutations with repeating symbols and mappings with nonbinary inputs. We also show that a subset of the new construction yields permutation sequences that are able to correct insertion and deletion errors as well. Finally, we show that long binary sequences, formed by concatenating the columns of binary permutation matrices, are subsets of the Levenshtein insertion/deletion correcting codes. / Prof. H. C. Ferreira
59

Generalization of Signal Point Target Code

Billah, Md Munibun 01 August 2019 (has links)
Detecting and correcting errors occurring in the transmitted data through a channel is a task of great importance in digital communication. In Error Correction Coding (ECC), some redundant data is added with the original data while transmitting. By exploiting the properties of the redundant data, the errors occurring in the data from the transmission can be detected and corrected. In this thesis, a new coding algorithm named Signal Point Target Code has been studied and various properties of the proposed code have been extended. Signal Point Target Code (SPTC) uses a predefined shape within a given signal constellation to generate a parity symbol. In this thesis, the relation between the employed shape and the performance of the proposed code have been studied and an extension of the SPTC are presented. This research presents simulation results to compare the performances of the proposed codes. The results have been simulated using different programming languages, and a comparison between those programming languages is provided. The performance of the codes are analyzed and possible future research areas have been indicated.
60

Design and Simulation of Coded-Modulation Using Turbo Trellis Coding and Multi-Layer Modulations

Khalili, Fatemeh, January 2017 (has links)
No description available.

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