Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 32 for “"turbo codes"”.
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On the Design of Turbo Codes
This thesis is about Turbo codes - codes constructed via parallel concatenation of two recursive convolutional encoders linked by an interleaver. The focus of the work is on the understanding and design of Turbo codes. This includes thorough investigation of central components that influence Turbo …
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The Study of Turbo Codes and Iterative Decoding
… the average BER performance of the finite-length turbo codes in the form of a lower bound. The amount of computation needed to obtain the lower bound is much less than a full simulation of the iterative turbo decoding. Based on the proposed methodologies, we discuss the guideline for the design of …
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Simulating Turbo codes using a modular simulation platform
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2002.
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Evaluation of Soft Output Decoding for Turbo Codes
Evaluation of soft output decoding for turbo codes is presented. Coding theory related to this research is studied, including convolutional encoding and Viterbi decoding. Recursive systematic convolutional (RSC) codes and nonuniform interleavers commonly used in turbo code encoder design are …
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An investigation of Turbo Codes over Mobile Wireless Channels
Turbo codes have been the subject of much research in recent years, producing results very close to the theoretical limit set by Shannon. The codes have been successfully implemented in satellite and video conferencing systems and provision has been made in 3rd generation mobile systems. These …
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GMD Decoding of Euclidean -Space Codes and Iterative Decoding of Turbo Codes
… and leads to a better understanding of the turbo decoding algorithm. Specifically, a simplified stopping criterion based on the characteristics of the phase trajectories is provided.
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Source-controlled block turbo coding
This thesis proposes the use of block turbo codes for transmitting nonuniform binary memoryless sources over AWGN channels. As opposed to standard convolutional turbo codes, block turbo codes are known to achieve good performance for high code rates, up to 98% of the channel capacity for uniform …
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Performance of turbo coded DS-CDMA systems in correlated and uncorrelated satellite communication channels
This thesis aims at presenting the perfonnance of turbo codes in the correlated and uncorrelated satellite fading channel. Turbo codes are known to give very good perfonnance results in A WGN channels, especially for very large input message length codes or interleaver sizes. It can be shown that …
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Iterative Detection and Decoding for Wireless Communications
Turbo codes are a class of forward error correction (FEC) codes that offer energy efficiencies close to the limits predicted by information theory. The features of turbo codes include parallel code concatenation, recursive convolutional encoding, nonuniform interleaving, and an associated iterative …
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Trellis-based iterative decoding of block codes for satellite ATM
… channels such as satellite links, error control codes are needed to provide high performance at very low Signal-to-Noise Ratios (SNRs). Turbo Codes or concatenated codes with iterative decoding, can achieve a performance very close to the Shannon limit. They are the most powerful codes known so …
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Implementation of a Turbo Decoder on a Configurable Computing Platform
Turbo codes are a new class of codes that can achieve exceptional error performance and energy efficiency at low signal-to-noise ratios. Decoding turbo codes is a complicated procedure that often requires custom hardware if it is to be performed at acceptable speeds. Configurable computing machines …
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Performance Optimization and Parallelization of Turbo Decoding for Software-Defined Radio
… standards to share a common architecture. Turbo codes offer excellent error-correcting performance, however, turbo decoders are one of the most computationally complex baseband tasks of a wireless receiver. Next generation wireless standards such as Worldwide Interoperability for Microwave …
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Packet data communications over coded CDMA with hybrid type-II ARQ
… dissertation presents in-depth investigation of turbo-coded CDNIA systems in packet data communication terminology. It is divided into three parts; (1) CDMA with hybrid FEC/ARQ in deterministic environment, (2) CDMA with hybrid FEC/ARQ in random access environment and (3) an implementation issue …
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Turbo space-time coded modulation : principle and performance analysis
… in coding was achieved with the invention of turbo codes. Turbo codes approach Shannon capacity by displaying the properties of long random codes, yet allowing efficient decoding. Coding alone, however, cannot fully address the problem of multipath fading channel. Recent advances in …
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Dynamic Code Selection Method for Content Transfer in Deep Space Network
… a new content transfer protocol based on RaptorQ codes and turbo codes together with a real-time channel prediction model to maximize file transfer from space vehicles to the Earth stations. While turbo codes are used to correct channel errors, RaptorQ codes are applied to eliminate the need for …
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Design Of Fountain Codes With Error Control
… via a comrelay by using distributed lt codes over a binary erasure channel (bec), and designing fountain codes with error control property by integrating lt codes with turbo codes over a binary input additive white gaussian noise (bi-awgn) channel. A simple yet efficient technique for …
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A Smart Implementation of Turbo Decoding for Improved Power Efficiency
Error correction codes are a means of including redundancy in a stream of information bits to allow the detection and correction of symbol errors during transmission. The birth of error correction coding showed that Shannon's channel capacity could be achieved when transmitting information through …
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Novel receiver architectures for mobile communications
… in this thesis. With the great interest in turbo codes for commercial cellular mobile communications such as WCDMA and cdma2000, the proposed receiver architectures are successfully employed in channel estimation for turbo decoding in Rayleigh fading channels.
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Implementation and Performance of an Improved Turbo Decoder on a Configurable Computing Machine
Turbo codes are a recently discovered class of error correction codes that achieve near-Shannon limit performance. Because of their complexity and highly parallel nature, turbo-coded applications are well suited for configurable computing. Field-programmable gate arrays (FPGAs), which are the main …
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