检索结果-内蒙古大学图书馆

Conference on Applications of Digital Image Processing XXXV

作者： Ahn, Y. J. Han, W. J. Sim, D. G. Kwangwoon Univ Dept Comp Engn Wolgye 1 Dong Seoul 139701 South Korea Gachon Univ Dept Software Dev & Management Gyeonggi Do 461701 South Korea

ISBN: (纸本)9780819492166

High Efficiency Video Coding (HEVC) is the latest standardization efforts of ISO/IEC MPEG and ITU-T VCEG for further improving the coding efficiency of H.264/AVC standard. It has been reported that HEVC can provide comparable subjective visual quality with H.264/AVC at only half bit-rates in many cases. In this paper, decoder complexities between HEVC and H.264/AVC are studied for providing initial complexity estimates of the HEVC decoder compared with the H.264/AVC decoder. For this purpose, several selected coding tools including intra prediction, motion compensation, transform, loop filters and entropy coder have been analyzed in terms of number of operations as well as their statistical differences.

关键词： High Efficiency Video Coding HEVC decoder complexity video compression MPEG VCEG JCT-VC

来源：评论

学校读者我要写书评

暂无评论

complexity modeling for motion compensation in H.264/AVC decoder

Complexity modeling for motion compensation in H.264/AVC dec...

引用

IEEE International Conference on Image Processing (ICIP 2007)

作者： Lee, Szu-Wei Kuo, C. -C. Jay Univ So Calif Ming Hsieh Dept Elect Engn Signal & Image Processing Inst Los Angeles CA 90089 USA

ISBN: (纸本)9781424414369

A complexity model for motion compensation in the H.264/AVC decoder is proposed. This model considers a rich set of inter prediction modes allowed by H.264 as well as the relationship of motion vectors (MVs), which are related to cache miss performance. This model is verified by experimental results. Possible applications of the complexity model are also described. One application scenario is to integrate it in an H.264 encoder so that the encoder can estimate the decoding complexity and choose the best inter prediction mode to meet the complexity constraint of the target decoding platform.

关键词： H.264/AVC motion compensation decoder complexity rate-distortion optimization (RDO)

来源：评论

学校读者我要写书评

暂无评论

Capacity-Approaching TQC-LDPC Convolutional Codes Enabling Power-Efficient decoders

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2017年第1期65卷 1-13页

作者： Pisek, Eran Rajan, Dinesh Abu-Surra, Shadi Cleveland, Joseph R. PHAZR Inc Allen TX 75002 USA Southern Methodist Univ Dallas TX 75205 USA

In this paper, we develop a new capacityapproaching code, namely, parallel-concatenated (PC)-Low Density Parity Check (LDPC) convolutional code that is based on the parallel concatenation of trellis-based quasi-cyclic LDPC (TQCLDPC) convolutional codes. The proposed PC-LDPC convolutional code can be derived from any QC-LDPC block code by introducing the trellis-based convolutional dependency to the code. The capacity-approaching PC-LDPC convolutional codes are encoded through parallel concatenated trellis-based QC recursive systematic convolutional (RSC) encoder (namely, QCRSC encoder) that is also proposed in this paper. The proposed PC-LDPC convolutional code and the associated encoder retain a fine input granularity on the order of the lifting factor of the underlying block code. We also describe the corresponding trellisbased QC maximum a posteriori probability (namely, QC-MAP) decoder that efficiently decodes the PC-LDPC convolutional code. Performance and hardware implementation results show that the PC-LDPC convolutional codes with the QC-MAP decoder have two times lower complexity for a given bit-error-rate (BER), signal-to-noise ratio, and data rate, than conventional QC-LDPC block codes and LDPC convolutional codes. Moreover, the PC-LDPC convolutional code with the QC-MAP decoder outperforms the conventional QC-LDPC block codes by more than 0.5 dB for a given BER, complexity, and data rate and approaches Shannon capacity limit with a gap smaller than 1.25 dB. This low decoding complexity and the fine granularity make it feasible to efficiently implement the proposed capacityapproaching PC-LDPC convolutional code and the associated trellis-based QC-MAP decoder in next generation ultra-high data rate mobile systems.

关键词： LDPC convolutional code spatially-coupled LDPC decoder complexity IEEE802.11ad MAP decoder

来源：评论

学校读者我要写书评

暂无评论

Efficient adaptive coding scheme in mobile satellite communication channel

引用

IEE PROCEEDINGS-COMMUNICATIONS 1999年第6期146卷 337-342页

作者： Shin, SK Lee, SI You, MH Park, SK Sweeney, P Elect & Telecommun Res Inst Satellite Commun Syst Dept Yusong Gu Taejon 305606 South Korea Univ Surrey Sch Elect Engn Informat Technol & Math Ctr Commun Syst Res Guildford GU2 5XH Surrey England

The introduction of global mobile personal communications by satellite (GMPCS) systems makes it possible to provide high-quality services, especially by using low earth orbit (LEO) or medium earth orbit (MEO) satellites. In mobile satellite communication systems such as GMPCS systems, error correcting coding schemes are needed to achieve a desirable quality of service, and the coding scheme should be efficient in terms of the frequency spectrum as well as the power. Efficient coding schemes which employ trellis decoding methods with Reed-Solomon (RS) codes are proposed. These schemes can be used adaptively in time-varying fading conditions of mobile satellite communication channels. Simulations have been performed using a mobile satellite channel model as well as using an additive white Gaussian noise (AWGN) channel model. The results showed that the proposed schemes can achieve a better performance with less decoder complexity than a rate 1/2 constraint length 7 convolutional code in any fading environment.

关键词： frequency spectrum quality of service computational complexity time-varying fading condition global mobile personal communications by satellite mobile satellite communication channel error correcting coding medium Earth orbit LEO Mobile radio systems low Earth orbit mobile satellite communication additive white Gaussian noise channel RS codes Reed-Solomon codes adaptive codes trellis codes MEO AWGN channel fading environment high-quality services time-varying channels error correction codes performance GMPCS efficient adaptive coding scheme decoding fading channels trellis decoding decoder complexity personal communication networks AWGN channels Codes Satellite communication systems

来源：评论

学校读者我要写书评

暂无评论

Reduced complexity lattice-based multiple-input multiple-output schemes

引用

IET COMMUNICATIONS 2019年第10期13卷 1472-1481页

作者： Ouni, Nizar Tourki, Kamel Mohaisen, Manar Bouallegue, Ridha Univ Carthage Higher Sch Commun InnovCom Lab Tunis Tunisia Univ Tunis El Manar Natl Engn Sch Tunis Tunis Tunisia Huawei Technol Co France Res Ctr Math & Algorithm Sci Lab Paris France Korea Univ Technol & Educ Dept Elect Elect & Commun Engn Cheonan South Korea

Multiple-input multiple-output is being considered as a highly interesting topic for the new generation of wireless communication systems. The major challenge is how to enhance the link reliability while neither affecting the spectral efficiency nor the quality of service. To reduce the complexity of the maximum likelihood (ML) receiver, efforts have been focused on zero forcing (ZF) decoder using lattice reduction-aided (LRA) techniques. In this study, the authors propose a method that improves performance using the LRA-based precoding technique without increasing the decoder complexity. Their approach is to exploit the channel matrix to generate matrices for both the precoding and LRA detection technique. This makes it possible to achieve maximum orthogonality for the generated channel matrices while reducing considerably the noise effect. They focus on the use of the LRA-ZF for the ease of its implementation and low complexity. The proposed method outperforms LRA-minimum mean square error-based receiver and gets closer to ML receiver performance. The performance and complexity of the proposed scheme are discussed.

关键词： precoding matrix algebra MIMO communication least mean squares methods reduced complexity lattice-based multiple-input multiple-output schemes multiple-input multiple-output highly interesting topic wireless communication systems link reliability spectral efficiency quality of service maximum likelihood receiver lattice reduction-aided techniques LRA-based decoder complexity precoding generated channel matrices LRA-ZF low complexity LRA-minimum mean square error-based receiver ML receiver performance

来源：评论

学校读者我要写书评

暂无评论

Generalization Bounds for Neural Belief Propagation decoders

引用

IEEE TRANSACTIONS ON INFORMATION THEORY 2024年第6期70卷 4280-4296页

作者： Adiga, Sudarshan Xiao, Xin Tandon, Ravi Vasic, Bane Bose, Tamal Univ Arizona Dept Elect & Comp Engn Tucson AZ 85721 USA Meta Bellevue WA 98005 USA EpiSci San Diego CA 92064 USA

Machine learning based approaches are being increasingly used for designing decoders for next generation communication systems. One widely used framework is neural belief propagation (NBP), which unfolds the belief propagation (BP) iterations into a deep neural network and the parameters are trained in a data-driven manner. NBP decoders have been shown to improve upon classical decoding algorithms. In this paper, we investigate the generalization capabilities of NBP decoders. Specifically, the generalization gap of a decoder is the difference between empirical and expected bit-error-rate(s). We present new theoretical results which bound this gap and show the dependence on the decoder complexity, in terms of code parameters (blocklength, message length, variable/check node degrees), decoding iterations, and the training dataset size. Results are presented for both regular and irregular parity-check matrices. To the best of our knowledge, this is the first set of theoretical results on generalization performance of neural network based decoders. We present experimental results to show the dependence of generalization gap on the training dataset size, and decoding iterations for different codes.

关键词： Machine learning neural belief propagation generalization gap decoder complexity code parameters regular and irregular parity-check matrices

来源：评论

学校读者我要写书评

暂无评论

On viewing block codes as finite automata

引用

THEORETICAL COMPUTER SCIENCE 2003年第3期290卷 1775-1797页

作者： Shankar, P Dasgupta, A Deshmukh, K Rajan, BS Indian Inst Sci Dept Comp Sci & Automat Bangalore 560012 Karnataka India Univ Washington Dept Comp Sci & Engn Seattle WA 98195 USA Indian Inst Sci Dept Elect Commun Engn Bangalore 560012 Karnataka India

Block codes are viewed from a formal language theoretic perspective. It is shown that properties of trellises for subclasses of block codes called rectangular codes follow naturally from the Myhill Nerode theorem. A technique termed subtrellis overlaying is introduced with the object of reducing decoder complexity. Necessary and sufficient conditions for trellis overlaying are derived from the representation of the block code as a group, partitioned into a subgroup and its cosets. The conditions turn out to be simple constraints on coset leaders. It is seen that over-layed trellises are tail-biting trellises for which decoding is generally more efficient than that for conventional trellises. Finally, a decoding algorithm for tail-biting trellises is described, and the results of some simulations are presented. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： block codes tail-biting trellis decoder complexity maximum likelihood decoding

来源：评论

学校读者我要写书评

暂无评论

4K Real-Time and Parallel Software Video decoder for Multilayer HEVC Extensions

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2016年第1期26卷 169-180页

作者： Hamidouche, Wassim Raulet, Mickael Deforges, Olivier Inst Natl Sci Appl Rennes IMAGE Grp F-35708 Rennes France

Two High Efficiency Video Coding (HEVC) extensions, namely, the scalable HEVC (SHVC) extension and the multiview HEVC (MV-HEVC) extension, have been finalized in July 2014 by the Moving Picture Experts Group and Video Coding Experts Group. These two extensions enable additional features not covered in the first version of the HEVC standard such as spatial, fidelity, bitdepth, and color gamut scalability, as well as stereoscopic and multiview representations. In this paper, we propose a software parallel decoder architecture for the HEVC standard and its multilayer extensions, including SHVC and MV-HEVC extensions. The decoder consists of multiple instances of the OpenHEVC decoder, one instance to decode each layer with a communication between dependent layers to perform inter-layer predictions. The proposed multilayer HEVC decoder is parallel friendly and supports both wavefront parallelism to simultaneously process adjacent rows of the frame and frame-based parallelism to decode a set of temporal and spatial frames in parallel. Moreover, the most time-consuming operation introduced in the SHVC extension, namely, the resampling of the inter-layer reference picture in spatial scalability, is optimized in single instruction multiple data for x86 platform. We assess the complexity of the multilayer HEVC decoder with respect to the simulcast configuration. The multilayer decoder decoding two SHVC layers introduces in average 40%-71% additional complexity compared with the single layer HEVC decoder. Moreover, the low level optimizations with a hybrid parallel processing solution enable a real-time decoding of 4Kp60 enhancement layer on a 6-core Intel i7 processor running at 3.4 GHz.

关键词： decoder complexity High Efficiency Video Coding (HEVC) low level optimizations and parallel processing multilayer extensions multiview HEVC (MV-HEVC) scalable HEVC (SHVC)

来源：评论

学校读者我要写书评

暂无评论

Efficient Decoding for Generalized Quasi-Orthogonal Space-Time Block Codes

引用

WIRELESS PERSONAL COMMUNICATIONS 2013年第4期68卷 1731-1743页

作者： Taha, Zafar Q. Farraj, Abdallah K. Imam Univ Dept Elect Engn Riyadh Saudi Arabia Texas A&M Univ Dept Elect & Comp Engn College Stn TX 77843 USA

Space-time coding can achieve transmit diversity and power gain over spatially uncoded systems without sacrificing bandwidth. There are various approaches in coding structures, including space-time block codes. A class of space-time block codes namely quasi-orthogonal space-time block codes can achieve the full rate, but the conventional decoders of these codes experience interference terms resulting from neighboring signals during signal detection. The presence of the interference terms causes an increase in the decoder complexity and a decrease in the performance gain. In this article, we propose a modification to the conventional coding/decoding scheme that will improve performance, reduce decoding complexity, and improve robustness against channel estimation errors as well.

关键词： Space-time block code QOSTBC decoder complexity Transmit diversity Zero-forcing decoding

来源：评论

学校读者我要写书评

暂无评论

Power optimised channel coding in wireless sensor networks using low-density parity-check codes

引用

IET COMMUNICATIONS 2007年第6期1卷 1256-1262页

作者： Kashani, Z. Hajjarian Shiva, M. Univ Tehran Ctr Excellence Appl Electromagnet Syst Sch Elect & Comp Engn Tehran 14399 Iran

Energy consumption of low-density parity-check (LDPC) codes in different implementations is evaluated. decoder's complexity is reduced by finite precision representation of messages, that is, quantised LDPC decoder, and replacement of function blocks with look-up tables. It is shown that the decoder's energy consumption increases exponentially with the number of quantisation bits. For the sake of low-power consumption, 3-bit magnitude and 1-sign bit representation for messages are used in the decoder. It is concluded that high-rate Gallager codes are as energy efficient as the Reed-Solomon codes, which till now have been the first choice for wireless sensor networks (WSNs). Finally, it is shown that using LDPC codes in WSNs can be justified even more by applying the idea of trading the transmitter power with the decoder energy consumption. By exploiting the trade-off inherent in iterative decoding, the network lifetime is increased up to four times with the 3-6 regular LDPC code. Hence, it is inferred that the LDPC codes are more efficient than the block and the convolutional codes.

关键词： Reed-Solomon codes high-rate Gallager codes wireless sensor networks LDPC decoder complexity parity check codes decoder energy consumption iterative decoding computational complexity channel coding power optimised channel coding finite precision representation low-density parity-check codes

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：