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A NOVEL ALGORITHM OF SUPER-RESOLUtion RECONSTRUCtion FOR COMPRESSED VIDEO

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Journal of Electronics(china) 2007年第3期24卷 363-368页

作者： Xu Zhongqiang Zhu Xiuchang information Industry Ministry and Jiangsu province {2. Lab of image processing ＆ image communication Nanjing University of Posts ＆ Telecommunications Nanjing 210003 China

Super-Resolution (SR) technique means to reconstruct High-Resolution (HR) {2.s from a sequence of Low-Resolution (LR) observations,which has been a great focus for compressed video. Based on the theory of Projection Onto Convex Set (POCS),this paper constructs Quantization Constraint Set (QCS) using the quantization information extracted from the video bit stream. By combining the statistical properties of {2. and the Human Visual System (HVS),a novel Adaptive Quantization Constraint Set (AQCS) is proposed. Simulation results show that AQCS-based SR al-gorithm converges at a fast rate and obtains better performance in both objective and subjective quality,which is applicable for compressed video.

关键词：压缩视频超分辨率重建量化约束集 SR算法

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A WYNER-ZIV VIDEO CODING METHOD UTILIZING MIXTURE CORRELAtion NOISE MODEL

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Journal of Electronics(china) 2012年第Z2期 197-203页

作者： Hu Xiaofei* ** Zhu Xiuchang* (image processing and image communication key laboratory, nanjing university of posts and telecommunications, nanjing 210003, {12.) **(college of Geography and Biological information, nanjing university of posts and telecommunications, nanjing 210003, {12.)

In Wyner-Ziv (WZ) Distributed Video Coding (DVC), correlation noise model is often used to describe the error distribution between WZ frame and the side {2.. The accuracy of the model can influence the performance of the video coder directly. A mixture correlation noise model in Discrete Cosine Transform (DCT) domain for WZ video coding is established in this paper. Different correlation noise estimation method is used for direct current and alternating current coefficients. Parameter estimation method based on expectation maximization algorithm is used to estimate the Laplace distribution center of direct current frequency band and Mixture Laplace-Uniform Distribution Model (MLUDM) is established for alternating current coefficients. Experimental results suggest that the proposed mixture correlation noise model can describe the heavy tail and sudden change of the noise accurately at high rate and make significant improvement on the coding efficiency compared with the noise model presented by DIStributed COding for Video sERvices (DISCOVER).

关键词： Transform domain Wyner-Ziv (WZ) DIStributed COding for Video sERvices (DISCOVER) Video coding Correlation noise model Mixture Laplace-Uniform Distribution Model (MLUDM)

A novel multi-relay cross-layer cooperative communication strategy based on Jackson queuing model

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Science china(information Sciences) 2010年第4期53卷 842-853页

作者： XU XiaoRong1,2. & ZHENG BaoYu1 1Institute of Signal processing and Transmission, nanjing {2. of posts and telecommunications, nanjing 210003, china 2.7} of Telecommunication engineering, Hangzhou Dianzi {2., Hangzhou 310018, china Institute of Signal processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China college of Telecommunica{2. engineering Hangzhou Dianzi University Hangzhou China

A novel multi-relay cooperative communication strategy based on Jackson queuing model is pro-posed, which is implemented via a cross-layer design between the physical (PHY) layer and the medium access control (MAC) layer. In the PHY layer, we focus mainly on system outage performance by analyzing in detail the relationship between the SNR threshold and the outage probabilities. While in the MAC layer, system model is treated as a Jackson queuing network, and the queue discipline for each node is assumed to be GI/M/1 model. System throughput and delay performance for the proposed strategy are also illustrated. Simulation results of the proposed cross-layer scheme are presented to validate our theoretical derivations. It is revealed that, the number of cooperative nodes influences system outage performance at high spectral efficiency regimes in the PHY layer while the proposed strategy provides a better throughput and delay performance than conventional schemes in the MAC layer.

关键词： multi-relay cooperative communication cross-layer design Jackson queuing model outage prob- abilities GI/M/1 model system throughput delay performance

Robust cooperative spectrum sensing schemes for fading channels in cognitive radio networks

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Science china(information Sciences) 2011年第2期54卷 348-359页

作者： YUE WenJing1,2. ZHENG BaoYu1,2. MENG QingMin1, CUI JingWu1 & XIE PeiZhong1 1Institute of Signal processing and Transmission, nanjing {2. of posts and telecommunications, nanjing 210003, china 2.epartment of Electronic engineering, Shanghai Jiaotong {2., Shanghai 2.02.0, china Institute of Signal processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China Department of Electronic engineering Shanghai Jiaotong University Shanghai China

In cognitive radio systems, cooperative spectrum sensing can detect the presence of the primary user accurately. In practice, however, since the sensing observations are forwarded to a data collector through fading channels, the sensing performance is severely degraded. To deal with this problem, in this paper, we first propose a secondary user selection based cooperative spectrum sensing method to improve sensing performance by decreasing the reporting errors introduced by the fading channels. More specifically, only the secondary users with better signal-to-noise ratio (SNR) for reporting channels are allowed to send their local binary decisions (0 or 1) to the data collector while the others will send nothing. Additionally, we further propose a diversity based cooperative spectrum sensing method which applies existing space-time coding. By exploiting space diversity in CR network, the reporting errors introduced by the fading channel can be decreased and then the sensing performance is improved significantly. For either proposed cooperative spectrum sensing method, the sensing performance is derived and the analytical performance results are given. Our analysis and numerical results verify that proposed methods outperform the conventional cooperative spectrum sensing with OR-rule by taking into account the error effect on the reporting channels.

关键词： cognitive radio (CR) spectrum sensing energy detection diversity technique space-time coding

Optimal power allocation for cognitive relay networks: amplify-and-forward versus selection relay

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Science china(information Sciences) 2011年第4期54卷 861-872页

作者： YUE WenJing 1,2.ZHENG BaoYu 1,2.MENG QingMin 1,YUE WenJie 3 & CUI JingWu 1 1 Institute of Signal processing and Transmission,nanjing {2. of posts and telecommunications,nanjing 210003,china 2.Department of Electronic engineering,Shanghai Jiaotong {2.,Shanghai 2.02.0,china 3 Shanxi Institute of Educational Science,Taiyuan 030009,china Institute of Signal processing and Transmission Nanjing University of Posts and Telecommunications Nanjing China Department of Electronic engineering Shanghai Jiaotong University Shanghai China Shanxi Institute of Educational Science Taiyuan China

We consider a cognitive relay network which is defined by a source,a destination,and cognitive relay nodes and primary user *** this network,a source is assisted by cognitive relay nodes which allow coexisting with primary user nodes by imposing severe constraints on the transmission power so that they operate below the noise floor of primary user *** this paper,we mainly study the power allocation strategies of this system to minimize the outage probability subject to total and individual power constraints for cognitive relay nodes and subject to interference constraints for primary user nodes.A relay transmission scheme,namely amplify-and-forward (AF),is *** first present an optimal power allocation (OPA) scheme to minimize the system outage probability,based on instantaneous channel state information among the source,destination and relay nodes and mean channel gains between primary user nodes and cognitive ***,we propose a selection AF scheme (S-AF) where the single best relay is chosen to assist in the transmission and study power allocation strategy for S-AF to minimize outage *** analytical power allocation strategies have been validated through numerical *** results indicate that the AF with OPA and S-AF with OPA have significantly better outage behavior and average throughput than AF and S-AF schemes *** also find that S-AF with OPA achieves a higher throughput,and hence lower outage probability than AF with OPA.

关键词： cognitive radio (CR) relay networks power allocation outage probability

基于灰度预测和灰色关联分析的离散余弦变化图像隐藏算法(英文)

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china communica{2.s 2013年第7期10卷 57-70页

作者：黄海平黄世超陈九天王汝传 college of Computer Nanjing University of Posts and Telecommunications Jiangsu High Technology Research key laboratory for Wireless Sensor Networks key laboratory of Broadband Wireless {2.tion and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Jiangsu Provincial key laboratory for Computer {2. processing Technology Soochow University

Traditional information hiding algorithms cannot maintain a good balance of capacity,invisibility and *** this paper,a novel blind colour {2. information hiding algorithm based on grey prediction and grey relational analysis in the Discrete Cosine Transform(DCT) domain is ***,this algorithm compresses the secret {2. losslessly based on the improved grey prediction GM(1,1)(IGM) *** then chooses the blocks of rich texture in the cover {2. as the embedding regions using Double-dimension Grey Relational Analysis(DGRA).Finally,it adaptively embeds the compressed secret bits stream into the DCT domain mid-frequency coefficients,which are decided by those blocks' Double-Dimension Grey Correlation Degree(DGCD) and Human Visual System(HVS).This method can ensure an adequate balance between invisibility,capacity and *** results show that the proposed algorithm is robust against JPEG compression(46.72. 6 dB when the compression quality factor is 90%),Gaussian noise(45.531 3 dB when the parameter is(0,0.000 5)) etc.,and it is a blind information hiding algorithm that can be extracted without an original carrier.

关键词：信息隐藏算法离散余弦变换域灰色关联分析灰色预测图像隐藏自适应压缩人类视觉系统 JPEG压缩

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Optimum Watermarking Algorithm Based-on Cost Function

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Optimum Watermarking Algorithm Based-on Cost Function

Nonlinear Prediction with Deep Recurrent Neural Networks for Non-Blind Audio Bandwidth Extension

2.07 8th International Conference on Electronic Measurement & Instruments（ICEMI’2.07）

作者： Lian Xu 1 Hu Xuelong 1 2.Zhang Haiqiang 1 (1.School of information engineering Yangzhou {2. Yangzhou 2.5009 china) 2.Jiangsu province key Lab for image processing and communication nanjing {2. of Post and {12. nanjing 2.5006 china)

This paper proposed a cost function in DWT domain,which combines the two most critical properties including the transparency and *** on the cost function,the optimum location can be found for *** modeling to the wavelet coefficient by the GGD （Generalized Gaussian Density）,we proposed the method of estimation of shape parameter,which corresponding to LOD （Locally Optimum Detection） also can be used in watermarking *** utilizing the proposed approach,a good compromise between the transparency and robustness can be gotten in experiments.

关键词： Watermarking wavelet GGD cost function LOD

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china communica{2.s 2018年第4期15卷 72-85页

作者： Lin Jiang Ruimin Hu Xiaochen Wang Weiping Tu Maosheng Zhang National engineering Research Center for Multimedia Software School of Computer Science Wuhan University Wuhan 430072 China Institute of Big Data and internet Innovation Hunan University of Commerce Changsha 410205 China Software college East China University of Technology Nanchang 330013 China Collaborative Innovation Center for Economics crime investigation and prevention technology Jiangxi Province Nanchang 330103China Hubei key laboratory of Multimedia and Network {2.tion engineering Wuhan University Wuhan 430072 China Collaborative Innovation Center of Geospatial Technology Wuhan 430079 China

Non-blind audio bandwidth extension is a standard technique within contemporary audio codecs to efficiently code audio signals at low bitrates. In existing methods, in most cases high frequencies signal is usually generated by a duplication of the corresponding low frequencies and some parameters of high frequencies. However, the perception quality of coding will significantly degrade if the correlation between high frequencies and low frequencies becomes weak. In this paper, we quantitatively analyse the correlation via computing mutual information value. The analysis results show the correlation also exists in low frequency signal of the context dependent frames besides the current frame. In order to improve the perception quality of coding, we propose a novel method of high frequency coarse spectrum generation to improve the conventional replication method. In the proposed method, the coarse high frequency spectrums are generated by a nonlinear mapping model using deep recurrent neural network. The experiments confirm that the proposed method shows better performance than the reference methods.

关键词： audio coding non-blind audiobandwidth extension context correlation deeprecurrent neural network

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Modeling and Simulation of Position for the Stratospheric ISAR System

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Modeling and Simulation of Position for the Stratospheric IS...