检索结果-内蒙古大学图书馆

IEEE International Symposium on Information Theory and Its Applications

作者： Dumitrescu, Sorina Wu, Xiaolin McMaster Univ Hamilton ON Canada

ISBN: (纸本)0780391519

We investigate the complexity of joint source-channel maximum a posteriori (MAP) decoding of a Markov sequence which is first encoded by a source code, then encoded by a convolutional code, and sent through a noisy memoryless channel. As established previously the MAP decoding can be performed by a Viterbi-like algorithm on a trellis whose states are triples of the states of the Markov source, source coder and convolutional coder. The large size of the product space (in the order of K-2 N, where K is the number of source symbols and N is the number of states of the convolutional coder) appears to prohibit such a scheme. We show that for finite impulse response convolutional codes, the state space size of joint source-channel decoding can be reduced to O(K-2+N log N), hence the decoding time becomes O(TK2 + TN log N), where T is the length in bits of the decoded bitstream. We further prove that an additional complexity reduction can be achieved when K > N, if the logarithm of the source transition probabilities satisfy the so-called Monge property. This decrease becomes more significant as the tree structure of the source code is more unbalanced. The reduction factor ranges between O(KIN) (for a fixed-length source code) and O(K/log N) (for Golomb-Rice code).

关键词： joint source-channel decoding maximum a posteriori sequence estimation finite-state machine complexity

来源：评论

学校读者我要写书评

暂无评论

Estimation of redundancy in compressed image and video data for joint source-channel decoding

Estimation of redundancy in compressed image and video data ...

引用

IEEE Global Telecommunications Conference (GLOBECOM 03)

作者： Nguyen, H DuHamel, P Alcatel Res & Invovat Dept F-91460 Marcoussis France

ISBN: (纸本)0780379748

joint source-channel decoding of Variable Length Codes for image and video streaming transmission over unreliable links, such as wireless networks, is a subject of increasing interest. In this article, we first provide an analysis of available redundancy in compressed video data produced by some commonly used standardized codecs. Then, we show that significant improvement decoding performance can be achieved when additional image and video data properties are taken into consideration. Finally, performance results for improving video decoding over wireless channels are presented.

关键词： source redundancy variable length codes compressed image and video decoding joint source-channel decoding

来源：评论

学校读者我要写书评

暂无评论

Concatenated Polar Codes and joint source-channel decoding

Concatenated Polar Codes and Joint Source-Channel Decoding

引用

作者： Wang, Ying Texas A&M University

学位级别：Ph.D.

In this dissertation, we mainly address two issues: 1. improving the finite-length performance of capacity-achieving polar codes; 2. use polar codes to efficiently exploit the source redundancy to improve the reliability of the data storage system. In the first part of the dissertation, we propose interleaved concatenation schemes of polar codes with outer binary BCH and convolutional codes to improve the finite-length performance of polar codes. For asymptotically long blocklength, we show that our schemes achieve exponential error decay rate which is much larger than the sub-exponential decay rate of standalone polar codes. In practice we show by simulation that our schemes outperform stand-alone polar codes decoded with successive cancellation or belief propagation decoding. The performance of concatenated polar and convolutional codes can be comparable to stand-alone polar codes with list decoding in the high signal to noise ratio regime. In addition to this, we show that the proposed concatenation schemes require lower memory and decoding complexity in comparison to belief propagation and list decoding of polar codes. With the proposed schemes, polar codes are able to strike a good balance between performance, memory and decoding complexity. The second part of the dissertation is devoted to improving the decoding performance of polar codes where there is leftover redundancy after source compression. We focus on language-based sources, and propose a joint-source channel decoding scheme for polar codes. We show that if the language decoder is modeled as erasure correcting outer block codes, the rate of inner polar codes can be improved while still guaranteeing a vanishing probability of error. The improved rate depends on the frozen bit distribution of polar codes and we provide a formal proof for the convergence of that distribution. Both lower bound and maximum improved rate analysis are provided. To compare with the non-iterative joint list decoding scheme for

关键词： Polar codes finite length concatenation error decay rate source redundancy joint source-channel decoding frozen bit distribution improved rate Thesis

来源：评论

学校读者我要写书评

暂无评论

Low complexity joint source-channel decoding for transmission of wavelet compressed images

引用

Journal of Southeast University(English Edition) 2006年第2期22卷 148-152页

作者：殷玮玮梅中辉吴乐南东南大学信息科学与工程学院南京210096

To utilize residual redundancy to reduce the error induced by fading channels and decrease the complexity of the field model to describe the probability structure for residual redundancy, a simplified statistical model for residual redundancy and a low complexity joint source-channel decoding（JSCD） algorithm are proposed. The complicated residual redundancy in wavelet compressed images is decomposed into several independent 1-D probability check equations composed of Markov chains and it is regarded as a natural channel code with a structure similar to the low density parity check （LDPC） code. A parallel sum-product （SP） and iterative JSCD algorithm is proposed. Simulation results show that the proposed JSCD algorithm can make full use of residual redundancy in different directions to correct errors and improve the peak signal noise ratio （PSNR） of the reconstructed image and reduce the complexity and delay of JSCD. The performance of JSCD is more robust than the traditional separated encoding system with arithmetic coding in the same data rate.

关键词： joint source-channel decoding sum-product algorithm generalized distribution law wavelet compressed image

来源：评论

学校读者我要写书评

暂无评论

joint source-channel turbo decoding of entropy-coded sources

引用

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2001年第9期19卷 1680-1696页

作者： Guyader, A Fabre, E Guillemot, C Robert, M INRIA IRISA F-35042 Rennes France

We analyze the dependencies between the variables involved in the source and channel coding chain. This analysis is carried out in the framework of Bayesian networks, which provide both an intuitive representation for the global model of the coding chain and a way of deriving joint (soft) decoding algorithms. Three sources of dependencies are involved in the chain: 1) the source model, a Markov chain of symbols;2) the source coder model, based on a variable length code (VLC), for example a Huffman code;and 3) the channel coder, based on a convolutional error correcting code. joint decoding relying on the hidden Markov model (HMM) of the global coding chain is intractable, except in trivial cases. We advocate instead an iterative procedure inspired from serial turbo codes, in which the three models of the coding chain are used alternately. This idea of using separately each factor of a big product model inside an iterative procedure usually requires the presence of an interleaver between successive components. We show that only one interleaver is necessary here, placed between the source coder and the channel coder. The decoding scheme we propose can be viewed as a turbo algorithm using alternately the intersymbol correlation due to the Markov source and the redundancy introduced by the channel code. The intermediary element, the source coder model, is used as a translator of soft information from the bit clock to the symbol clock.

关键词： Bayesian network data compression entropy coding iterative decoding joint source-channel decoding probabilistic inference soft decoding turbo code variable length code

来源：评论

学校读者我要写书评

暂无评论

ON joint source-channel decoding AND INTERFERENCE CANCELLATION IN CDMA-BASED LARGE-SCALE WIRELESS SENSOR NETWORKS

ON JOINT SOURCE-CHANNEL DECODING AND INTERFERENCE CANCELLATI...

引用

IEEE International Conference on Acoustics, Speech and Signal Processing

作者： Chathura Illangakoon Pradeepa Yahampath Department of Electrical Engineering University of Manitoba

ISBN: (纸本)9781479903573

Motivated by potential applications in wireless sensor networks, we consider the problem of communicating a large number of correlated analog sources over a Gaussian multiple-access channel using non-orthogonal code-division multiple-access (CDMA). We present a joint source-channel decoder which exploits the inter-source correlation for interference reduction in the CDMA channel. This decoder uses a linear minimum mean square error (MMSE) multi-user detector (MUD) in tandem with a MMSE joint source decoder for multiple sources to achieve a computational complexity that scales with the number of sources. However, iterative exchange of extrinsic information between the MUD and the joint source decoder leads to improved interference cancellation. Experimental results obtained with decoding observations from Gaussian random fields show that the proposed iterative decoder can achieve a considerable performance gain compared to a non-iterative decoder. The results also show that the iterative decoder is robust against the performance degradation due to correlated interference in a non-orthogonal CDMA channel.

关键词： Multi-terminal source coding joint source-channel decoding Iterative decoding CDMA Multi-user detection Code division multiple access Multiuser detection Iterative decoding decoders Wireless sensor networks joints decoding mud degradation of performance disturbance suppression CANCELLATIONS Combined source-channel coding

来源：评论

学校读者我要写书评

暂无评论

joint ITERATIVE source-channel decoding OF THREE CORRELATED sourceS 4

JOINT ITERATIVE SOURCE-CHANNEL DECODING OF THREE CORRELATED ...

引用

4th IEEE International Conference on Network Infrastructure and Digital Content (IEEE IC-NIDC)

作者： Zheng Jian Bie Hongxia Xu Dijia Lei Chunyang Zhang Xuekun Beijing Univ Posts & Telecommun Beijing 100876 Peoples R China Zunyi Med Coll Dept Med Informat Engn Zunyi 563003 Peoples R China

ISBN: (纸本)9781479947348

Considering the fact that when the signal-to-noise ratio (SNR) is less than a certain threshold, the bit error rate (BER) performance of joint source-channel decoding (JSCD) will become more vulnerable to channel noise. To further improve the performance of JSCD, a practical and efficient algorithm, named joint iterative source-channel decoding (JISCD), is proposed in this paper, in which the performance of the JSCD is enhanced by the additional iteration to exchange additive information between multiple sources. The simulation results prove that an additional coding gain can be obtained by the proposed algorithm. Moreover, the algorithm can be considered as an extension of the JSCD.

关键词： joint iterative source-channel decoding joint source-channel decoding correlated source iterative decoding Quasi-Cyclic Low-Density Parity-Check codes

来源：评论

学校读者我要写书评

暂无评论

joint source channel Soft decoding Using Dynamic Redundancy Detection

Joint Source Channel Soft Decoding Using Dynamic Redundancy ...

引用

International Conference on Networks Security, Wireless Communications and Trusted Computing

作者： Xiang, Weiwei Xiang, Weiwei Lu, Peizhong Informat Sci & Technol Inst Dept Commun Engn Zhengzhou Peoples R China SW Inst Electron & Telecom Techn Shanghai Peoples R China

ISBN: (纸本)9780769536101

Multi media transmission over error-prone channels such as wireless channels has recently motivated the research on the joint source-channel (de)coding (JSCC, JSCD) technique. In this paper, we present a new JSCD method, which extends the joint area to the process of demodulation soft decision to enlarge the application fields of JSCD. The proposed method designs a technique of dynamic source redundancy detection and generalizes the Viterbi algorithm in a TDM system with scrambler. Simulation results show that our new method can obtain substantial improvements with a minor increasing of complexity, especially in the bad channel environment. For a TDM system with 30% occupied slots, the gain in SNR is around 4.4dB when SER reaches 10(-2).

关键词： joint source-channel decoding time-division multiplexing soft decision Viterbi decoding

来源：评论

学校读者我要写书评

暂无评论

Parallel vs. sequential belief propagation decoding of LDPC codes over GF(q) and Markov sources

引用

PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2007年第2期378卷 329-335页

作者： Yacov, N. Efraim, H. Kfir, H. Kanter, I. Shental, O. Bar Ilan Univ Minerva Ctr IL-52900 Ramat Gan Israel Bar Ilan Univ Dept Phys IL-52900 Ramat Gan Israel Tel Aviv Univ Dept Elect Engn Syst IL-69978 Tel Aviv Israel

A sequential updating scheme (SUS) for belief propagation (BP) decoding of LDPC codes over Galois fields, GF(q), and correlated Markov sources is proposed and compared with the standard parallel updating scheme (PUS). A thorough experimental study of various transmission settings indicates that the convergence rate, in iterations, of the BP algorithm for the SUS is about one half of that for the PUS, independent of the finite field size q. Moreover, this 1/2 factor appears regardless of the correlations of the source and the channel's noise model, while the error correction performance remains unchanged. These results may imply on the 'universality' of the one half convergence speed-up of SUS decoding. A comparison to the dynamics of physical spin systems is also addressed. (c) 2007 Elsevier B.V. All rights reserved.

关键词： LDPC codes over GF(q) Markov sources belief propagation joint source-channel decoding sequential updating dynamics of spin systems

来源：评论

学校读者我要写书评

暂无评论

Video Error Correction Using Soft-Output and Hard-Output Maximum Likelihood decoding Applied to an H.264 Baseline Profile

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2015年第7期25卷 1161-1174页

作者： Caron, Francois Coulombe, Stephane Vantrix Corp Montreal PQ H3G 1T7 Canada Ecole Technol Super Montreal PQ H3C 1K3 Canada

Error concealment has long been identified as the last line of defense against transmission errors. Since error handling is outside the scope of video coding standards, decoders may choose to simply ignore corrupted packets or attempt to decode their content. In this paper, we present a novel joint source-channel decoding approach that can be applied to received video packets containing transmission errors. Soft-output information is combined with our novel syntax-element-level maximum likelihood decoding framework to effectively extract valid macroblocks from corrupted H.264 slices. Simulation results show that our video error correction strategy provides an average peak signal-to-noise ratio (PSNR) improvement near 2 dB compared to the error concealment approach used by the H.264 reference software, as well as an average PSNR improvement of 0.8 dB compared to state-of-the-art error concealment. The proposed method is also applicable when only hard-information is available, in which case it performs better than state-of-the-art error concealment especially in high error conditions. Finally, in our simulations, the proposed method increased the decoder computational complexity by only 5% to 20%, making it applicable for real-time applications.

关键词： H.264 joint source-channel decoding maximum likelihood decoding real time video applications video error correction

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：