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Content-adaptive robust error concealment for packet-lossy H.264 video streaming

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第z1期7卷 41-47页

作者： LIAO Ning YAN Dan quan zi-yi MEN Ai-dong Multimedia Center School of Telecommunication Engineering Beijing University of Posts & Telecom Beijing 100876 China Multimedia Center School of Telecommunication Engineering Beijing University of Posts & Telecom Beijing 100876 China Multimedia Center School of Telecommunication Engineering Beijing University of Posts & Telecom Beijing 100876 China Multimedia Center School of Telecommunication Engineering Beijing University of Posts & Telecom Beijing 100876 China

In this paper, we present a spatio-temporal post-processing error concealment (EC) algorithm designed initially for a H.264 video-streaming scheme over packet-lossy networks. It aims at optimizing the subjective quality of the restored video under the constraints of low delay and computational complexity, which are critical to real-time applications and portable devices having limited resources. Specifically, it takes into consideration the physical property of motion field in order to achieve more meaningful perceptual video quality, in addition to the improved objective PSNR. Further, a simple bilinear spatial interpolation approach is combined with the improved boundary-match (B-M) based temporal EC approach according to texture and motion activity analysis. Finally, we propose a low complexity temporal EC method based on motion vector interpolation as a replacement of the B-M based approach in the scheme under low-computation requirement, or as a complement to further improve the scheme's performance in applications having enough computation resources. Extensive experiments demonstrated that the proposal features not only better reconstruction, objectively and subjectively, than JM benchmark, but also robustness to different video sequences.

关键词： Error concealment, Error control, H.264/AVC, Video streaming, Lossy transmission

Robust spatio-temporal error concealment for packet- lossy H.264 video transmission

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The Journal of China Universities of Posts and Telecommunications 2006年第3期13卷 87-92页

作者： LIAO Ning YAN Dan quan zi-yi MEN Ai-dong Multimedia Center Beijing University of Posts and TelecommunicationsBeijing 100876 China

In this article, a spatio-temporal post-processing error concealment algorithm designed initially for a H.264 video-streaming scheme over packet-lossy networks has been presented. It aims at optimizing subjective quality of restored video and the conventional objective metric, peak signal-to-noise ratio （PSNR）, as well, under the constraints of low delay and computational complexity, which are critical to real-time applications and portable devices having limited resources. Specifically, it takes into consideration physical property of motion to achieve more meaningful perceptual video quality. Further, a content-adaptive bilinear spatial interpolation approach and a temporal error concealment approach are combined under a unified boundary match criterion based on texture and motion activity analysis. Extensive experiments have demonstrated that the proposal not only result in better reconstruction, objectively and subjectively, than the reference software model benchmark, but also results in better robustness to different video sequences.

关键词： error concealment error control H.264/JVT video transmission lossy transmission

Rate estimate for regular LDPCA codec in distributed video coding

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The Journal of China Universities of Posts and Telecommunications 2012年第1期19卷 50-54页

作者： MING Yang-yang YANG Bo quan zi-yi MEN Ai-dong School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Accumulated low density parity check （LDPCA） codec is proposed for DISCOVER project in distributed video coding （DVC）, which offers flexible coding rate. Although it can use feedback channel to adapt the rate to the correlation of the video, but in real applications, using feedback channel can not always be possible. To solve this problem, some researchers proposed estimating the code rate at the encoder but the performance was not very good. Based on their researches, this paper considers the impact of convergence rate for iteration on rate estimate, which can be calculated using its check matrix. As a pilot study, this paper pays attention to the regular LDPCA codec. At the same time, it considers the impact of deviation in the estimated crossover probability, which gives some constraints to rate estimate. In the experiment, the proposed algorithm can improve the rate-distortion performance by up to 1 dB-1.2 dB.

关键词： LDPCA distributed video coding rate estimate regular LDPCA codec crossover probability deviation

Improvement and Analysis of Carrier-Interferometry Orthogonal Frequency Division Multiplexing System

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The Journal of China Universities of Posts and Telecommunications 2005年第4期12卷 38-42页

作者： HE Jian-hui quan zi-yi MEN Ai-dong School of Telecommunication Engineering Beijing University of Posts and telecommtmications Beijing 100876 P. R. China

This paper proposes to use Fast Fourier Transform （ FFT ） / Inverse Fast Fourier Transform （IFFT）, instead of vector-matrix multiplication, to implement the spreading/despreoding in Carrier-Interferometry Orthogonal Frequency Division Multiplexing （ CI/OFDM） and Pseudo-Orthogonal Carrier lnterferometry OFDM （PO-CI/OFDM）. That can improve the signal processing efficiency of CI/OFDM and PO-CI/OFDM systems by about 2N/log2N and 2N/（ 1 ＋ log2 N） times respectively and dose not make any difference to the system function and performance. Moreover, the effi- ciency benefits will increase with the increase of the number of sub-carriers. In addition to that, we point out that the transmitter of CI/OFDM is actually technically equivalent to that of a single-carrier system with cyclic-prefix and the receiver of CI/OFDM is a typical OFDM receiver with CI despreading. Hence the low Peak-to-Average Power Ratio （PA- PR） property and high anti-fading performance of CI/OFDM system can be well explained .

关键词： OFDM Carrier Interferometry (CI) Pseudo-Orthogonal Carrier-Interfer ometry (PO-CI) Fast Fourier Transform (FFT) Inverse Fast Fourier Transform (IFFT) Code Division Multiplexing (CDM) OFDM-CDM

Construction of LDPC codes over GF(q) with modified progressive edge growth

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The Journal of China Universities of Posts and Telecommunications 2009年第5期16卷 103-106,113页

作者： CHEN Xin , MEN Ai-dong, YANG Bo, quan zi-yi School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China [a]School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing 100876 China

A parity check matrix construction method for constructing a low-density parity-check （LDPC） codes over GF（q）（q〉2） based on the modified progressive edge growth （PEG） algorithm is introduced. First, the nonzero locations of the parity check matrix are selected using the PEG algorithm. Then the nonzero elements are defined by avoiding the definition of subcode. A proof is given to show the good minimum distance property of constructed GF（q）-LDPC codes. Simulations are also presented to illustrate the good error performance of the designed codes.

关键词： LDPC codes over GF(q) progressive edge growth large minimum distance

Riemann-Hilbert Problem and Multiple High-order Poles Solutions of the Focusing mKdV Equation with Nonzero Boundary Conditions

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Acta Mathematicae Applicatae Sinica 2025年第1期41卷 234-251页

作者： zi-yi WANG Shou-fu TIAN Jin-jie YANG School of Mathematics China University of Mining and TechnologyXuzhou 221116China

The focusing modified Korteweg-de Vries(mKdV)equation with multiple high-order poles under the nonzero boundary conditions is first investigated via developing a Riemann-Hilbert(RH)*** begin with the asymptotic property,symmetry and analyticity of the Jost solutions,and successfully construct the RH problem of the focusing mKdV *** solve the RH problem when 1/S_(11)(k)has a single highorder pole and multiple high-order ***,we derive the soliton solutions of the focusing mKdV equation which corresponding with a single high-order pole and multiple high-order poles,***,the dynamics of one-and two-soliton solutions are graphically discussed.

关键词： Riemann-Hilbert approach focusing mKdV equation nonzero boundary conditions multiple high-order poles soliton solutions

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三维子带视频编码的率失真优化码率控制

北京邮电大学学报 2007年第3期30卷 79-82,87页

作者：廖宁全子一门爱东北京邮电大学电信工程学院北京100876

阐述了目前广泛使用的位平面截断算法的理论依据,并指出其次最佳性.提出均方误差最小意义上的最佳三维子带码率分配算法,该算法在任意给定码率限制条件下都能获得最优率失真性能.对比实验还表明,比特分配策略的选择将严重地影响子带分... 详细信息

阐述了目前广泛使用的位平面截断算法的理论依据,并指出其次最佳性.提出均方误差最小意义上的最佳三维子带码率分配算法,该算法在任意给定码率限制条件下都能获得最优率失真性能.对比实验还表明,比特分配策略的选择将严重地影响子带分级编码系统的压缩性能.

关键词：三维小波/子带视频编码码率控制码率分配率失真优化

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可分级视频编码结构优化的差错恢复编码方法

北京邮电大学学报 2007年第3期30卷 32-35页

作者：阎金全子一门爱东北京邮电大学电信工程学院北京100876

提出了一种在丢包环境下的基于H.264的可伸缩视频编码(SVC)扩展的率失真(RD)优化宏块模式判决模型.在RD模型中加入时间级的优化参数.编码器每编码完一帧图像后,都以编码块为单位计算信源编码失真和误差扩散失真,并将计算结果存储在失真... 详细信息

提出了一种在丢包环境下的基于H.264的可伸缩视频编码(SVC)扩展的率失真(RD)优化宏块模式判决模型.在RD模型中加入时间级的优化参数.编码器每编码完一帧图像后,都以编码块为单位计算信源编码失真和误差扩散失真,并将计算结果存储在失真映射表中用于计算下一个编码图像的端到端失真.实验结果表明,在丢包环境下,优化后的率失真模型的差错恢复性能比优化前有明显提高.

关键词：可分级视频编码率失真模型差错恢复

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一种有效的FG-LDPC译码方法

北京邮电大学学报 2007年第2期30卷 63-66页

作者：周伟门爱东赵黎晔全子一北京邮电大学电信工程学院北京100876

基于有限几何低密度奇偶校验码(FG-LDPC)译码性能、复杂度和时延,提出了一种混合比特翻转(BF)和大数逻辑译码(MLG)的译码方法.在比特翻转译码过程中,提出了一种有效度量相关校验可靠性的方法.经过BF迭代译码后,再由MLG译码.译码过程不... 详细信息

基于有限几何低密度奇偶校验码(FG-LDPC)译码性能、复杂度和时延,提出了一种混合比特翻转(BF)和大数逻辑译码(MLG)的译码方法.在比特翻转译码过程中,提出了一种有效度量相关校验可靠性的方法.经过BF迭代译码后,再由MLG译码.译码过程不涉及浮点运算,降低了复杂度,减小了时延.仿真表明,新的译码方法比原有加权比特翻转(WBF)算法性能提高了0.3 dB.

关键词：低密度奇偶校验码比特翻转译码大数逻辑译码和积算法