检索结果-内蒙古大学图书馆

作者： Billah, Md Munibun Utah State University

学位级别：M.S.

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.

关键词： error correction coding Trellis Coded Modulation Viterbi Algorithm QPSK QAM Electrical and Computer Engineering

来源：评论

学校读者我要写书评

暂无评论

Posouzení vlivu dělícího poměru na pasivní optickou síť

Posouzení vlivu dělícího poměru na pasivní optickou s...

引用

作者： Gallo, Martin Brno University of Technology

Práca sa zaoberá najnovším štandardom pasívnych optických sietí NG-PON2, jeho vrstvovým modelom, ktorého súčasťou je ochranné zabezpečenie pri prenose po optickom m... 详细信息

Práca sa zaoberá najnovším štandardom pasívnych optických sietí NG-PON2, jeho vrstvovým modelom, ktorého súčasťou je ochranné zabezpečenie pri prenose po optickom médiu. Implementuje a popisuje simulačné prostredie. Posudzuje vplyv deliaceho pomeru pomocou tohto prostredia vytvoreného z definovaného modelu, pričom porovnáva rôzne scenáre použitia. Diskutuje možné zdroje chýb simulačného modelu v porovnaní s reálnym.

关键词： Pasívna optická sieť NG-PON2 Protichybové opravne kódovanie RS kódy BCH kódy Deliaci pomer VPIphotonics Passive optical network NG-PON2 error correction coding RS codes BCH codes Split ratio VPIphotonics Text

来源：评论

学校读者我要写书评

暂无评论

Algorithm Development and VLSI Implementation of Energy Efficient Decoders of Polar Codes

Algorithm Development and VLSI Implementation of Energy Effi...

引用

作者： Xu, Jingwei Texas A&M University

With its low error-floor performance, polar codes attract significant attention as the potential standard error correction code (ECC) for future communication and data storage. However, the VLSI implementation complexity of polar codes decoders is largely influenced by its nature of in-series decoding. This dissertation is dedicated to presenting optimal decoder architectures for polar codes. This dissertation addresses several structural properties of polar codes and key properties of decoding algorithms that are not dealt with in the prior researches. The underlying concept of the proposed architectures is a paradigm that simplifies and schedules the computations such that hardware is simplified, latency is minimized and bandwidth is maximized. In pursuit of the above, throughput centric successive cancellation (TCSC) and overlapping path list successive cancellation (OPLSC) VLSI architectures and express journey BP (XJBP) decoders for the polar codes are presented. An arbitrary polar code can be decomposed by a set of shorter polar codes with special characteristics, those shorter polar codes are referred to as constituent polar codes. By exploiting the homogeneousness between decoding processes of different constituent polar codes, TCSC reduces the decoding latency of the SC decoder by 60% for codes with length n = 1024. The error correction performance of SC decoding is inferior to that of list successive cancellation decoding. The LSC decoding algorithm delivers the most reliable decoding results; however, it consumes most hardware resources and decoding cycles. Instead of using multiple instances of decoding cores in the LSC decoders, a single SC decoder is used in the OPLSC architecture. The computations of each path in the LSC are arranged to occupy the decoder hardware stages serially in a streamlined fashion. This yields a significant reduction of hardware complexity. The OPLSC decoder has achieved about 1.4 times hardware efficiency improvement compa

关键词： error correction coding VLSI Thesis

来源：评论

学校读者我要写书评

暂无评论

FontCode: Embedding Information in Text Documents Using Glyph Perturbation

引用

ACM TRANSACTIONS ON GRAPHICS 2018年第2期37卷 15-15页

作者： Xiao, Chang Zhang, Cheng Zheng, Changxi Columbia Univ Dept Comp Sci 616 Schapiro New York NY 10027 USA

We introduce FontCode, an information embedding technique for text documents. Provided a text document with specific fonts, our method embeds user-specified information in the text by perturbing the glyphs of text characters while preserving the text content. We devise an algorithm to choose unobtrusive yet machine-recognizable glyph perturbations, leveraging a recently developed generative model that alters the glyphs of each character continuously on a font manifold. We then introduce an algorithm that embeds a user-provided message in the text document and produces an encoded document whose appearance is minimally perturbed from the original document. We also present a glyph recognition method that recovers the embedded information from an encoded document stored as a vector graphic or pixel image, or even on a printed paper. In addition, we introduce a new error-correction coding scheme that rectifies a certain number of recognition errors. Lastly, we demonstrate that our technique enables a wide array of applications, using it as a text document metadata holder, an unobtrusive optical barcode, a cryptographic message embedding scheme, and a text document signature.

关键词： Font manifold glyph perturbation error correction coding text document signature

来源：评论

学校读者我要写书评

暂无评论

A Joint Layered Scheme for Reliable and Secure Mobile JPEG-2000 Streaming

引用

ACM TRANSACTIONS ON MULTIMEDIA COMPUTING COMMUNICATIONS AND APPLICATIONS 2012年第3期8卷 30-30页

作者： Zhu, Xinglei Chen, Chang Wen SUNY Buffalo Dept Comp Sci & Engn Buffalo NY 14260 USA

This article presents a novel joint layered approach to simultaneously achieve both reliable and secure mobile JPEG-2000 image streaming. With a priori knowledge of JPEG-2000 source coding and channel coding, the proposed joint system integrates authentication into the media error protection components to ensure that every source-decodable media unit is authenticated. By such a dedicated design, the proposed scheme protects both compressed JPEG-2000 codestream and the authentication data from wireless channel impairments. It is fundamentally different from many existing systems that consider the problem of media authentication separately from the other operations in the media transmission system. By utilizing the contextual relationship, such as coding dependency and content importance between media slices for authentication hash appending, the proposed scheme generates an extremely low authentication overhead. Under this joint layered coding framework, an optimal rate allocation algorithm for source coding, channel coding, and media authentication is developed to guarantee end-to-end media quality. Experiment results on JPEG-2000 images validate the proposed scheme and demonstrate that the performance of the proposed scheme is approaching its upper bound, in which case no authentication is applied to the media stream.

关键词： Algorithms Performance Security Multimedia authentication authentication schemes mobile media communication communication system security error correction coding streaming authentication

来源：评论

学校读者我要写书评

暂无评论

A new innovation in channel coding for speech coders

A new innovation in channel coding for speech coders

引用

IEE Colloquium on Low Bit-Rate Speech coding for Future Applications

作者： L.K. Ong A.M. Kondoz B.G. Evans Centre for Satellite Engineering Research University of Surrey Guildford Surrey UK

The use of channel coding in low bit rate speech coders face a performance upper bound with the limited redundancy permitted. Thus, the speech quality can degrade in bad channel transmission conditions. This paper describes a error control configuration which exploits source redundancy to enhance the performance of the channel decoder, possibly beyond maximum likelihood performance.< >

关键词： Decoding error correction coding Redundancy Speech coding

来源：评论

学校读者我要写书评

暂无评论

Modified trellis decoding of simple product codes and their error performance in Gaussian channels

Modified trellis decoding of simple product codes and their ...

引用

Proceedings of GLOBECOM 1995 Mini

作者： Honary Soyjaudah Ramsawock Yu Wai Man Y K L Lancaster Univ. UK University of Mauritius Mauritius University of Lancaster UK

Previously proposed trellis decoding of array codes cannot be applied to simple product codes having any number of rows and columns. A modified scheme is proposed that can be used with all square and rectangular codes. It is illustrated by simulation study, that using soft decision trellis decoding we can correct a number of errors approaching 3 dmin and that even hard decision trellis decoding corrects errors in excess of dmin. The performance curves of a wide range of product codes are presented and compared.

关键词： Product codes error correction coding Decoding error analysis Gaussian channels

来源：评论

学校读者我要写书评

暂无评论

Coherent optical fibre digital PPM employing Reed-Solomon error correcting codes

Coherent optical fibre digital PPM employing Reed-Solomon er...

引用

IEE Colloquium on Coherent Optical Communications

作者： R.A. Cryan R.T. Unwin Department of Electrical & Electronic Engineering Huddersfield Polytechnic

In recent literature digital PPM has been shown to be an effective modulation format for optical communication channels. In this paper the authors show how Reed-Solomon codes, used in conjunction with digital PPM, can further improve receiver sensitivity. They present computer predicted results, at a bit-rate of 565 Mbit/s and a wavelength of 1.5 mu m, comparing both uncoded and coded homodyne digital PPM with coherent PCM. It is concluded that the Reed-Solomon coded system offers an improvement of 4 dB over the uncoded system and 9 dB over homodyne PSK PCM.< >

关键词： Digital communication error correction coding error analysis Optical communication Optical fibers Pulse position modulation

来源：评论

学校读者我要写书评

暂无评论

Development of an error correction system in teletext for PAL-TV signals

Development of an error correction system in teletext for PA...

引用

1990 International Broadcasting Convention, IBC 1990

作者： S. Moriyama T. Kuroda O. Yamada Y. Tomida Japan Broadcasting Corporation Japan Sanyo Electric Company Limited Japan

There are four teletext systems, systems A to D, which are recommended by the CCIR. System D, developed in Japan, has adopted a powerful error correction system, known as BEST (burst and random error correction system for teletext), for NTSC-TV systems. A novel transmission system, in which BEST can be multiplexed with the PAL-TV signal, has been invented, as a teletext for China which uses Chinese characters, while developing devices for transmission and reception. Using these devices, indoor and outdoor experiments were carried out in cooperation with the Ministry of Radio, Film and TV of China to compare BEST with WST (world system teletext). The author describes the outline of BEST for the PAL-TV signals and the results of the experiments comparing it with WST.< >

关键词： error correction coding Teletext TV broadcasting

来源：评论

学校读者我要写书评

暂无评论

1/2" composite digital VTR (PAL version)

1/2" composite digital VTR (PAL version)

引用

1990 International Broadcasting Convention, IBC 1990

作者： R. Scott K. Suesada Y. Oba K. Murayama Panasonic Broadcast Europe UK Matsushita Elecrric Indusrrial Company Limited Japan NHK (Japan Broadcasting Corporation) Japan

The 1/2" digital format includes a significant number of new developments in recording technology. They provide the format with input/output signal specifications equivalent to D-2 but in a cassette size only slightly larger than MII, and with two hours play time. Thus, tape running costs and tape storage costs are reduced. In particular, this is important for producing a compact digital cart machine with a large library. All applications, from ENG/EFP to studio recording, post production, and on-air playback via cart machine, can be achieved in a single format, contributing greatly to studio automation and reducing labour costs whilst maintaining picture and sound quality of the highest standards. In terms of making the 1/2" digital format a viable commercial product, Panasonic are producing a range of products from compact camera/recorders to post-production and automated recording/playback systems. Applications for the product are much wider than only broadcast or professional video, to include such areas as multi-media computer systems, industrial, educational, data storage and medical applications.< >

关键词： error correction coding Communication standards Video recording

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：