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A new side information estimate based Distributed Video Coding algorithm for wireless multimedia sensor networks

International Journal of Advancements in Computing technology 2012年第1期4卷 320-326页

作者： Xiao, Fu Liu, Jinkai Sun, Lijuan Wang, Ruchuan Nanjing University of Posts and Telecommunications China Jiangsu High Technology Research Key Laboratory for Wireless Sensor Networks China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education China

Video compression can reduce the amount of data information for wireless multimedia sensor networks(WMSNs). Compared with the traditional video coding algorithms, big gap existed in coding performance for Distributed Video Coding (DVC). In order to improve the efficiency of side information estimation, a novel hash-based side information estimation algorithm is proposed in this paper. For the regions of the Wyner-Ziv frame which cannot coding and decoding accurately, Discrete Cosine Transform (DCT) low-frequency coefficients of DCT is extracted according to the criteria of ROI for entropy coding. Then decoded DCT low-frequency coefficients for bidirectional hash motion estimation is utilized by decoder, which enables the decoder to choose between past and future reference frames for frame interpolation to generate best side information. Experimental results show that our proposed algorithm can gain more accurate motion estimation in the intense motion region. The algorithm can also reduce the rate, improve the quality of decoded image, and decrease the energy consumption of sensor nodes ultimately, which is important for WMSNs.

关键词： Discrete cosine transforms

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QoE-Driven Distributed Media Services in D2D communications Underlaying Cellular networks

QoE-Driven Distributed Media Services in D2D Communications ...

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IEEE International Conference on communications Workshops

作者： Mingkai Chen Lei Wang Jianxin Chen Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications) Ministry of Education

ISBN: (纸本)9781509015269

Device-to-device (D2D) communication has been widely studied to improve network performance and been considered as a potential technological component for the next generation communication. As Quality of Experience (QoE) is the major determining factor for the media service, we aim at promoting user's QoE Mean of Score (MOS) value for dynamic cellular networks. In this paper, we focus on the problem of heterogeneous media service distribution in D2D communications underlaying cellular networks. Firstly, we propose an innovative distributed media service scheme based on QoE models that jointly solve the massive media content dissemination issue for cellular networks. Moreover, our work maximizes users' QoE satisfaction by jointly considering media-aware, popularity function and priority function. Then, we propose a novel resource allocation algorithm based on the popularity function to optimize the total users' QoE satisfaction and avoid the influence of D2D interference. Numerical simulation results demonstrate the effectiveness of our proposed schemes.

关键词： Cellular networks communication Research Popularity

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The research on joint distributed source coding and network coding for wireless multicast network

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Journal of Computational Information Systems 2013年第3期9卷 1147-1156页

作者： Liu, Ying Yang, Zhen Mei, Zhonghui Kong, Yuanyuan Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

This paper considers the problem of transmitting correlated information from multiple sources to multiple receivers, where every receiver seeks to recover all of the original sources. In order to improve the efficiency of network transmission, we combine interflow network coding and distributed source coding using syndromes (DISCUS). Furthermore, for wireless multicast multi-hop network, we propose an adaptive transmission algorithm with target of minimum energy consumption based on the above practical joint scheme. The simulation results verify the validation of theoretical results in the paper. Copyright © 2013 Binary Information Press.

关键词： network coding

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Pilot Assignment Based on Graph Coloring with Sum-Rate Maximization in Cell-Free Massive MIMO

Pilot Assignment Based on Graph Coloring with Sum-Rate Maxim...

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International Conference on Computer and communications (ICCC)

作者： Rongheng Chen Hong Wang Rongfang Song Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781665409513

To mitigate the severe effect of pilot contamination, a novel graph coloring (NGC) based algorithm is applied to pilot assignment in cell-free massive multiple-input multiple-output (MIMO) systems. Specifically, firstly, the potential pilot contamination intensity among users is calculated by utilizing the large-scale fading between users and access points (APs). Then, the contamination threshold is set to perform the sparsification and an interference graph describing the user interference relationship is constructed. Finally, the proposed algorithm is used to implement pilot assignment in the interference graph. In addition, an iterative grid search (IGS) approach is adopted to update the threshold to ensure that the system downlink sum-rate is maximized. The numerical results reveal that the proposed NGC pilot assignment algorithm with optimized thresholds can remarkably improve the system performance compared with previous pilot assignment schemes.

关键词： Fading channels System performance Simulation Interference Massive MIMO Downlink MIMO

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The method of gaze tracking based on iris detection

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International Journal of Information and communication technology 2013年第3-4期5卷 234-242页

作者： Zhang, Deng-Yin Wang, Zhou-Yang Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

This paper presents a new method of gaze tracking based on iris detection for images of human eyes captured by ordinary PC camera. In the basis of traditional iris detection, this paper improves the circle detection based on Hough transform by self-adopted angle step and in order to overcome the impact of light spot and noise, and presents the algorithm of interference-points elimination. The position user focus on screen is detected by comparing to the conference position after accurately calculating the centre pixel of pupil iris area. The proposed method is significant to the optimisation of network services and applications by apperceiving user experience (UE) through analysis sight movement sample of network user. Experimental results demonstrate the feasibility, the correct rate is 92%, 86% in 6×4, 8×6 screen block dividing respectively under normal circumstances. © 2013 Inderscience Enterprises Ltd.

关键词： Eye tracking

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Domain-epidemic spray and forward routing algorithm of opportunistic networks

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International Journal of Information and communication technology 2013年第3-4期5卷 332-342页

作者： Zhang, Deng-Yin Cui, Lei Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education Nanjing 210003 China

For the current opportunistic networks routing algorithms, their message arrival rate is not high and the delivery delay is large. This paper proposes a domain-epidemic spray and forward routing algorithm. The algorithm integrates redundancy and encounter prediction strategy. According to the probability of encounters between nodes, the nodes are divided into different domains. The spray and forward strategy is used between domains and the epidemic strategy is used to forward messages within a domain. Using the message confirmation mechanism and a list which is used to record the messages that have arrived to their destination, the new algorithm can effectively reduce redundant messages. Simulation results show our algorithm can effectively improve message arrival rate and reduce end-to-end delay to some extent. © 2013 Inderscience Enterprises Ltd.

关键词： Routing algorithms

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Interference alignment scheme for downlink multi-carrier MIMO cellular systems

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Journal of Computational Information Systems 2014年第3期10卷 1053-1064页

作者： Yang, Jie Song, Rongfang Dong, Heng Key Lab. of Broadband Wireless Communication and Sensor Network Technol. Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

In this paperwe propose a practical interference alignment (IA) scheme for the downlink cellular systems with multi-carrier transmission over multi-input-multi-output (MIMO) channels, where the interference is decompounded into two parts (inter-cell and intra-cell interference). IA is used to effectively mitigate inter-cell interferences, while the intra-cell interference is suppressed by subcarrier allocation so that some spatial degrees of freedom are released. Assuming L Base stations each with M antennas and K users (having N antennas), we present that a necessary condition for zero inter-cell interference is (L-N)K ≤ M-1. In contrast, for a single-carrier MIMO cellular networks, the corresponding condition is known to be N + M ≥ LK + 1, which does not hold usually. An iterative optimization algorithm for the proposed scheme is given, and numerical results show that the proposed scheme achieves a high spectral efficiency when the number of users is large and the number of transmit and receive antennas is limited. © 2014 Binary Information Press.

关键词： Cells

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Distributed multi-sensor tracking in wireless networks using nonparametric variant of sum-product algorithm

Distributed multi-sensor tracking in wireless networks using...

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Asia-Pacific Conference on communications

作者： Wei Li Zhen Yang Haifeng Hu Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

Graphical models have been widely applied in solving distributed inference problems in wireless sensor networks (WSNs). In this paper, we formulate the distributed multi-sensor tracking problem in a WSN as an inference problem on a factor graph. Using particle filtering methods, we propose a nonparametric variant of sum-product algorithm (SPA), called sequential particle-based SPA (SPSPA), for factor graphs to infer the multi-sensor target states over time. In the proposed algorithm, importance sampling methods are used to sample from message products, and the computational complexity of SPSPA is thus linear in the number of particles. We apply the SPSPA to a distributed multi-sensor tracking problem, and evaluate its performance in terms of the measurement noise and the number of particles.

关键词： wireless sensor networks wireless communication Filtering Noise measurement

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A data placement strategy based on clustering and consistent hashing algorithm in cloud computing

A data placement strategy based on clustering and consistent...

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International Conference on communications and networking in China (CHINACOM)

作者： Qiang Li Kun Wang Suwei Wei Xuefeng Han Lili Xu Min Gao Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781479959716

To reduce time delay of processing data and improve the efficiency of cloud computing, a clustering algorithm based on the principle of minimum distance is proposed to place user-based and item-based data, update cluster centre and the threshold dynamically. Besides, consistent hashing is combined to solve the fault tolerance and scalab.lity issues. In addition, Case-Based Reasoning (CBR) algorithm and item-based Coordination Filtering (CF) algorithms are used for filling sparse matrix to achieve better effect on the user-based clustering. Simulation results show that compared with data placement strategy based on K-means algorithm, this data placement strategy significantly improves clustering accuracy, greatly reduces delay of processing data and increases database scalab.lity and redundancy, thereby improving the efficiency of cloud computing.

关键词： Clustering algorithms Servers Heuristic algorithms Delay effects Sparse matrices Scalab.lity Cloud computing

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Arbitrary-Oriented Ship Detection Based on Rotation Region Locating networks in Large Scale Remote Sensing Images

Arbitrary-Oriented Ship Detection Based on Rotation Region L...

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International Conference on Image, Vision and Computing (ICIVC)

作者： Xipeng Liu Jianxin Chen Bin Kang Xuguang Zhang Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781728123264

Although deep learning has dominated the ship detection domain, it still has two challenges: arbitrary-oriented densely arranged ships cause detection omissions and large scale image contains redundant areas. This paper proposes an effective convolutional neural network framework for arbitrary-oriented ship detection in large scale and complex scenes. In this framework, we propose Cumulative Feature Pyramid networks for multi-receptive-field feature fusion, which enhances high-level semantic information at all scales. Based on the outputs of Region Proposal networks, Rotation Region Locating network predicts rotation bounding box of arbitrary-oriented ships and adopts rotation intersection over union to avoid the effect of ship dense arrangement. For large scale scenes, No-Ship Area Suppression uses OTSU algorithm to generate binary mask and then filter out non-ship regions to reduce redundant computations. Additionally, we firstly build a remote sensing image dataset for ship detection, which contains 4237 images and over 21200 ships. Experimental comparisons with the state-of-the-art approaches validate the effectiveness, accuracy and robustness of the proposed method.

关键词： Remote sensing Ship detection Deep learning Feature fushion Rotation region proposal Ships remote sensing remote sensing images Scale formation Machine Learning

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