检索结果-内蒙古大学图书馆

Proceedings of the Fifth International Conference on Body Area Networks

作者： Ki-Dong Lee Sang G. Kim Byung K. Yi LG Electronics San Diego CA

ISBN: (纸本)9781450300292

With the rapid growth of elderly population, u-healthcare service combined with advanced wireless networking technology is gaining popularity. The in-body and on-body nodes have very stringent requirements on transmit power and battery life. Furthermore, the wireless link in an in-body environment has a very high degree of path loss (e.g., 6.2 for deep tissue). Because of such worse settings for each communication node to deliver data packets to the other node, it is preferred to have a multi-hop network topology. This will ensure that each node can deliver data packets at a reduced expense of consuming a low level of transmit power, which is attractive to the live body of patients receiving the healthcare service due to the reduced level of radiation effect. We study an efficient method to deliver delay-intolerant data packets over multiple hops. As a solution we consider multiple description coding (MDC) and develop a mathematical formulation for packet-level scheduling of delay-intolerant MDC packets over multiple hops. The proposed method can be used as a simple guideline for applications to setting up a topology for a medical body area network (BAN) of each individual patient.

关键词： wireless sensor network u-healthcare service medical body area network (MBAN) applications applications scheduling multiple description coding

来源：评论

学校读者我要写书评

暂无评论

multiple description image coding with hybrid redundancy

Multiple description image coding with hybrid redundancy

引用

IEEE Asia Pacific Conference on Circuits and Systems

作者： Xu, Zhiming Lin, Zhiping Makur, Anamitra Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

ISBN: (纸本)9781424403868

This paper introduces a novel and effective multiple description image coding method by combination of polyphase down-sampling and multiple description scalar quantizers. Different from previous works, the natural redundancy in images is fully exploited by polyphase downsampling on the spatial domain of images to help improving reconstruction quality by effective error concealment. This approach is also flexible for generating more than two descriptions with very low complexity and for distributing redundancy among them to combat possible erasures. Simulation results on real images demonstrate high robustness of the proposed scheme for highly lossy networks with packet loss up to 87.5%.

关键词： multiple description coding polyphase downsampling hybrid redundancy error concealment erasure resilient image coding

来源：评论

学校读者我要写书评

暂无评论

Hybrid scalable video coding with multiple description and layered coding

Hybrid scalable video coding with multiple description and l...

引用

Conferenceon Visual Communications and Image Processing 2006

作者： Zhang, GJ Stevenson, RL Univ Notre Dame Dept Elect Engn Notre Dame IN 46556 USA

ISBN: (纸本)0819461172

We present a hybrid scalable video coding algorithm in which two types of scalabilities, i.e., layered scalability and parallel scalability, are combined to achieve higher order of flexibility for heterogeneous networks and mixed client requirements. In space domain, SNR scalable video coding is used to give layered scalability on frame quality;while in temporal domain, a multiple description approach, the multiple State Video coding (MSVC), provides parallel scalability to the base layer video. Two coarsely quantized sub-streams are yielded using MSVC and form the base layer. All residual signals of the video sequence are coded into a third sub-stream and form the enhancement layer. The hybrid scalable video protects the base layer using multiple description and has better performance than conventional layered scalable video when a base layer picture is damaged. It gives similar performance as SNR scalable video when the enhancement layer encounters errors. In general packet drop networks, the proposed scalable video achieves higher PSNR than the original MSVC video and single description video in high packet drop rate environments.

关键词： hybrid scalable video multiple description coding SNR scalable coding error resilience

来源：评论

学校读者我要写书评

暂无评论

Space-time multiple description video coding

Space-time multiple description video coding

引用

Conferenceon Visual Communications and Image Processing 2006

作者： Wang, D Canagarajah, N Bull, D Univ Bristol Image Commun Grp Ctr Commun Res Merchant Ventures BldgWoodland Rd Bristol BS8 1UB Avon England

ISBN: (纸本)0819461172

This paper develops a combined space-time multiple description video coding (ST-MDVC) scheme and corresponding error concealment methods in order to adapt to error prone packet networks, especially for multiple channels. It generates four descriptions, instead of two in most other MDVC schemes, with much lower redundancy than others. The three-loop slice group MDVC approach of [8] is used to achieve spatial description splitting. MDVC is very suitable for multiple channel environments, and especially able to maintain acceptable quality when some of these channels fail completely, i.e. in an on-off MDC environment, without experiencing any drifting problem. Our MDC scheme coupled with the proposed concealment approaches proved to be suitable not only for the on-off MDC environment case (data from one channel fully lost), but also for the case where only some packets are lost from one or more channels. Several steps to achieve high performance concealments are done with the received packets. Results show the promising performance with very low redundancy for both the balanced and unbalanced channel cases. Generating four descriptions make it more adapted to multi-path scenarios.

关键词： multiple description coding error concealment error resilience

来源：评论

学校读者我要写书评

暂无评论

Improved Resilience for Video Over Packet Loss Networks with MDC and Optimized Packetization

引用

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 2009年第10期19卷 1556-1560页

作者： Biswas, Moyuresh Frater, Michael R. Arnold, John F. Pickering, Mark R. Univ New S Wales Australian Def Force Acad Univ Coll Sch Informat Technol & Elect Engn Canberra ACT 2600 Australia

We investigate the problem of robust video transmission over lossy packet networks. A resilient video coding framework is important to ensure quality video over these networks. We propose a combination of a rate-distortion optimized multiple description codec and an integrated packetization method to constitute the error resilient codec. multiple description (MD) coding techniques utilize path-diversity (multiple paths between sender and receiver) in networks by sending the descriptions along different paths. Two different optimization controls for the MID codec are proposed that are suited to variable rates of packet loss for multipath transmission of the MD coded video. An optimized strategy for packetizing the descriptions is also proposed which guarantees that each packet is self-contained and efficient. Simulations done under various packet loss scenarios show the need for two different optimization strategies and also that the developed MD codec achieves significantly improved video quality when compared with similar techniques.

关键词： Error resilience multiple description coding packetization

来源：评论

学校读者我要写书评

暂无评论

Scalable coding with Side Information for Packet Loss Recovery

引用

IEEE TRANSACTIONS ON COMMUNICATIONS 2009年第8期57卷 2309-2319页

作者： Feldbauer, Christian Kleijn, W. Bastiaan Graz Univ Technol Signal Proc & Speech Commun Lab A-8010 Graz Austria KTH Royal Inst Technol Sound & Image Proc Lab Sch Elect Engn Stockholm Sweden AT&T Bell Labs Murray Hill NJ USA

This paper presents a packet loss recovery method that uses an incomplete secondary encoding based on scalar quantization as redundancy. The method is redundancy bit rate scalable and allows an adaptation to varying loss scenarios and a varying packeting strategy. The recovery is performed by minimum mean squared error estimation incorporating a statistical model for the quantizers to facilitate real.-time adaptation. A bit allocation algorithm is proposed that extends 'reverse water filling' to the problem of scalar encoding dependent variables for a decoder with a final estimation stage and available side information. We apply the method to the encoding of line-spectral frequencies (LSFs), which are commonly used in speech coding, illustrating the good performance of the method.

关键词： Robust coding packet loss media-specific forward error correction multiple description coding joint source channel coding speech coding

来源：评论

学校读者我要写书评

暂无评论

A Cross-Layer Design Framework for Robust IPTV Services Over IEEE 802.16 Networks

引用

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS 2009年第2期27卷 235-245页

作者： She, James Yu, Xiang Ho, Pin-Han Yang, En-Hui Univ Waterloo Dept Elect & Comp Engn Waterloo ON N2L 3G1 Canada

This paper introduces a cross-layer design framework for robust and efficient video multicasting over IEEE 802.16 (also known as WiMAX) networks in metropolitan areas. In the framework, multiple description coding (MDC) on scalable video bitstreams at the source for achieving multi-resolution robustness is jointly designed with superposition coding (SCM) on multicast signals at the channel to overcome multi-user channel diversity in wireless multicast. The ended multicast signals under the proposed framework can cope with multi-user channel diversity and mitigate the impact due to short-term channel fluctuations, which are the two most challenging issues in achieving robust and efficient video multicasting in metropolitan areas. We formulate the proposed framework and analyze its video quality performance in terms of the total receivable/recoverable bitstreams by a receiver. A heuristic methodology is developed for system parameter selection and performance optimization that can be applied to practical scenarios of video multicasting for IPTV services in WiMAX. Simulation is conducted based on actual standard video sequences to verify the proposed methodology on parameter selection anti performance optimization. Performance gains of the proposed cross-layer design framework in the presence of fading channel diversity are demonstrated..

关键词： Cross-layer design IEEE 802.16 IPTV multiple description coding scalable video coding superposition modulation WiMAX wireless multicast

来源：评论

学校读者我要写书评

暂无评论

Robust and Efficient Stream Delivery for Application Layer Multicasting in Heterogeneous Networks

引用

IEEE TRANSACTIONS ON MULTIMEDIA 2009年第1期11卷 166-176页

作者： Kobayashi, Masahiro Nakayama, Hidehisa Ansari, Nirwan Kato, Nei Tohoku Univ Grad Sch Informat Sci Sendai Miyagi 9808579 Japan Tohoku Inst Technol Fac Engn Dept Elect & Intelligent Syst Sendai Miyagi 9828577 Japan New Jersey Inst Technol Dept Elect & Comp Engn Adv Networking Lab Newark NJ 07102 USA

Application Layer Multicast (ALM) is highly expected to replace IP multicasting as the new technological choice for content delivery. Depending on the streaming application, ALM nodes will construct a multicast tree and deliver the stream through this tree. However, if a node resides in the tree leaves, it cannot deliver the stream to its descendant nodes. In this case, Quality of Service (QoS) will be compromised dramatically. To overcome this problem, Topology-aware Hierarchical Arrangement Graph (TRAG) was proposed. By employing multiple description coding (MDC), THAG first splits the stream into a number of descriptions, and then uses Arrangement Graph (AG) to construct node-disjoint multicast trees for each description. However, using a constant AG size in THAG creates difficulty in delivering descriptions appropriately across a heterogeneous network. In this paper, we propose a method, referred to as Network-aware Hierarchical Arrangement Graph (NHAG), to change the AG size dynamically to enhance THAG performance, even in heterogeneous networks. Finally, we evaluate the proposed scheme by experiments using the network simulator ns-2. By comparing our proposed method to THAG and SplitStream, we show that our method provides better performance in terms of throughput and QoS. The results indicate that our approach is more reliable than other methods in heterogeneous networks.

关键词： Application layer multicast content delivery multiple description coding streaming contents

来源：评论

学校读者我要写书评

暂无评论

System Scheduling for Multi-description Video Streaming Over Wireless Multi-Hop Networks

引用

IEEE TRANSACTIONS ON BROADCASTING 2009年第4期55卷 731-741页

作者： Zhou, Liang Geller, Benoit Zheng, Baoyu Wei, Anne Cui, Jingwu ENSTA ParisTech UEI F-75015 Paris France Nanjing Univ Posts & Telecommun Inst Signal Proc & Transmiss Nanjing 210003 Peoples R China Univ Toulouse 2 F-31703 Blagnac France

Providing real-time multimedia applications over wireless multi-hop networks is a challenging problem because the wireless channels are highly sensitive to delay, interference and topology changes. multiple description coding (MDC), as a new emerging error-resilient technique, has been widely used recently in wireless video transmission. Its fundamental principle is to generate multiple correlated descriptions such that each description approximates the source information with a certain level of fidelity. Inevitably, MDC introduces many description streams which may influence each other and thus, reasonable system scheduling is needed to provide a satisfied video quality. The novelty of this work is to investigate the optimal distributed scheduling for multiple competing MDC streams in a resource-limited wireless multi-hop network. This is achieved by joint optimization of MDC, rate control and multipath routing. Two joint optimal algorithms, namely a distributed rate control and routing (DRCR) and a simplified DRCR algorithm, are proposed to solve this problem with constraints that arise from the multiple description streams among multiple users via multiple paths. Both algorithms are designed in a distributed manner that is amenable to on-line implementation for wireless networks. Theoretical analysis and simulation results are provided which demonstrate the effectiveness of our proposed joint schemes.

关键词： Multipath routing multiple description coding rate control video transmission

来源：评论

学校读者我要写书评

暂无评论

M-description Lattice Vector Quantization: Index Assignment and Analysis

引用

IEEE TRANSACTIONS ON SIGNAL PROCESSING 2009年第6期57卷 2258-2274页

作者： Liu, Minglei Zhu, Ce Chongqing Univ Posts & Telecommun Sch Commun & Informat Engn Chongqing 400065 Peoples R China Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore

In this paper, we investigate the design of symmetric entropy-constrained multiple description lattice vector quantization (MDLVQ), more specifically, MDLVQ index assignment. We consider a fine lattice containing clean similar sublattices with S-similarity. Due to the S-similarity of the sublattices, an M-fraction lattice can be used to regularly partition the fine lattice with smaller Voronoi cells than a sublattice does. With the partition, the MDLVQ index assignment design can be translated into a transportation problem in operations research. Both greedy and general algorithms are developed to pursue optimality of the index assignment. Under high-resolution assumption, we compare the proposed schemes with other relevant techniques in terms of optimality and complexity. Following our index assignment design, we also obtain an asymptotical close-form expression of k-description side distortion. Simulation results on coding different sources of Gaussian, speech and image are presented to validate the effectiveness of the proposed schemes.

关键词： Index assignment lattice lattice vector quantization multiple description coding sublattice transportation problem

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：