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Relations Between Mobius and Coboundary Polynomials

MATHEMATICS IN COMPUTER SCIENCE 2012年第2期6卷 109-120页

作者： Jurrius, Relinde Eindhoven Univ Technol Dept Math & Comp Sci POB 513 NL-5600 MB Eindhoven Netherlands

It is known that, in general, the coboundary polynomial and the Mobius polynomial of a matroid do not determine each other. Less is known about more specific cases. In this paper, we will investigate if it is possible that the Mobius polynomial of a matroid, together with the Mobius polynomial of the dual matroid, define the coboundary polynomial of the matroid. In some cases, the answer is affirmative, and we will give two constructions to determine the coboundary polynomial in these cases.

关键词： Matroid theory Mobius polynomial Coboundary polynomial coding theory

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Advanced coding Techniques with Applications to Storage Systems

Advanced Coding Techniques with Applications to Storage Syst...

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作者： Nguyen, Phong Sy Texas A&M University

学位级别：Ph.D.

This dissertation considers several coding techniques based on Reed-Solomon (RS) and low-density parity-check (LDPC) codes. These two prominent families of errorcorrecting codes have attracted a great amount of interest from both theorists and practitioners and have been applied in many communication scenarios. In particular, data storage systems have greatly benefited from these codes in improving the reliability of the storage media. The first part of this dissertation presents a unified framework based on rate-distortion (RD) theory to analyze and optimize multiple decoding trials of RS codes. Finding the best set of candidate decoding patterns is shown to be equivalent to a covering problem which can be solved asymptotically by RD theory. The proposed approach helps understand the asymptotic performance-versus-complexity trade-off of these multiple-attempt decoding algorithms and can be applied to a wide range of decoders and error models. In the second part, we consider spatially-coupled (SC) codes, or terminated LDPC convolutional codes, over intersymbol-interference (ISI) channels under joint iterative decoding. We empirically observe the phenomenon of threshold saturation whereby the belief-propagation (BP) threshold of the SC ensemble is improved to the maximum a posteriori (MAP) threshold of the underlying ensemble. More specifically, we derive a generalized extrinsic information transfer (GEXIT) curve for the joint decoder that naturally obeys the area theorem and estimate the MAP and BP thresholds. We also conjecture that SC codes due to threshold saturation can universally approach the symmetric information rate of ISI channels. In the third part, a similar analysis is used to analyze the MAP thresholds of LDPC codes for several multiuser systems, namely a noisy Slepian-Wolf problem and a multiple access channel with erasures. We provide rigorous analysis and derive upper bounds on the MAP thresholds which are shown to be tight in some cases. This analy

关键词： coding theory data storage Reed-Solomon codes LDPC codes ISI channels soft-decdision decoding information theory multiuser communication capacity achieving codes Thesis

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Preface

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Electronic Notes in Discrete Mathematics 2013年 40卷 1-2页

作者： Faina, Giorgio Dipartimento di Matematica e Informatica Università di Perugia Perugia Italy

We are presenting in this volume the collection of extended abstracts of 66 talks that were presented at Combinatorics 2012 in Perugia, Italy. Combinatorics 2012 is the 17th in the series of combinatorics conferences ... 详细信息

关键词： coding theory Combinatorics Cryptology Design theory Finite Geometries Graph theory Matroid theory Optimisation Poset theory

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A Network coding Based Rarest-First Packet Recovery Algorithm for Transmitting Geocast Packets over Hybrid Sensor-Vehicular Networks

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第4期8卷 1-8页

作者： Hsu, Tz-Heng Lo, Ying-Chen So Taiwan Univ Dept Comp Sci & Informat Engn Tainan Taiwan

Vehicular ad hoc network (VANET) and road-side sensors are used to improve driving safety in many applications. Sensor nodes deployed along the roadside are used to sense road conditions and then deliver information about dangerous conditions to vehicles. In hybrid sensor-vehicular networks, new challenges arise and should be addressed. Geocasting can be used to perform the regional broadcast to deliver geographic-related safety, commercials, and advertisements messages. The challenging problem in geocasting is how to deliver packets to all the nodes within the geocast region with high efficiency but low overhead. Network coding is a special in-network data-processing technique that can potentially increase the network capacity and packet throughput in wireless networking environments. In this paper, a network coding based rarest-first packet recovery algorithm for transmitting geocast packets over hybrid sensor-vehicular-networks is proposed. The proposed algorithm can increase packet delivered ratio at each mobile node. As a result, the safety and transmission efficiency can be achieved simultaneously.

关键词： coding theory DATA packets & packeting ALGORITHMS HYBRID systems ROADS -- Safety measures VEHICULAR ad hoc networks (Computer networks) DATA transmission systems

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Network-coding-Based Cooperative ARQ Medium Access Control Protocol for Wireless Sensor Networks

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第1期8卷 1-9页

作者： Antonopoulos, Angelos Verikoukis, Christos Telecommun Technol Ctr Catalonia CTTC Barcelona 08860 Spain

We introduce a novel Medium Access Control (MAC) protocol for Automatic Repeat reQuest-based (ARQ-based) cooperative wireless sensor networks. Using network coding techniques, we achieve a better network performance in terms of energy efficiency without compromising the offered Quality of Service (QoS). The proposed solution is compared to other cooperative schemes, while analytical and simulation results are provided to evaluate our protocol.

关键词： WIRELESS sensor networks coding theory COMPUTERS -- Access control COMPUTER network protocols NETWORK performance (Telecommunication) ENERGY consumption QUALITY of service

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An Efficient Reliable Communication Scheme in Wireless Sensor Networks Using Linear Network coding

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第unknown期2012卷 1-11页

作者： Wang, Jin Wang, Xiumin Zhang, Shukui Zhu, Yanqin Jia, Juncheng Hefei Univ Technol Sch Comp & Informat Hefei 230009 Peoples R China Soochow Univ Sch Comp Sci & Technol Suzhou 215006 Peoples R China Nanjing Univ State Key Lab Novel Software Technol Nanjing 210093 Jiangsu Peoples R China

We address the modeling and design of linear network coding (LNC) for reliable communication against multiple failures in wireless sensor networks (WSNs). To fulfill the objective, we design a deterministic LNC scheme RDLC based on the average number of path failures simultaneously happening in the network other than the maximum number of path failures. The scheme can significantly improve the network throughput comparing with the traditional approaches. In our study, we also investigate the potential of random linear code RRLC for providing reliable communication in WSNs and prove the low bound of the probability that the RRLC can provide the reliable communication. Finally, extensive simulation experiments have been conducted, and the results demonstrate the effectiveness of the proposed LNC schemes.

关键词： WIRELESS sensor networks ENERGY consumption COMPUTER reliability LINEAR systems coding theory COMPUTER engineering FAILURE Analysis System (Computer system)

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Network Coded Wireless Cooperative Multicast with Minimum Transmission Cost

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第10期8卷 1-12页

作者： Wang, Xiumin Wang, Jin Zhang, Shukui Soochow Univ Sch Comp Sci & Technol Suzhou 215006 Peoples R China Hefei Univ Technol Sch Comp & Informat Hefei 230009 Peoples R China Nanjing Univ State Key Lab Novel Software Technol Nanjing 210093 Jiangsu Peoples R China

We study multicasting over wireless lossy links. Instead of downloading all the data from the source node, we allow the destination nodes themselves to locally exchange the packets, as local communication within a cluster achieves higher packet reception probability with less transmission cost. However, when shall we stop the transmission from the source node? If the source stops too early, the destination nodes locally cannot reconstruct all the original packets, while if the source stops too late, the benefit of cooperative data exchange cannot be fully exploited. In this paper, we propose a network coded hybrid source and cooperative exchange scheme to determine when to stop the source sending and start the exchange process, so as to minimize the total transmission cost. For the case when the clusters are predefined, we derive the expected total transmission cost with our hybrid scheme. Our theoretical results show that under a special condition, the source node should keep sending the packets until all the destinations get the complete information. For the case when the clusters are not predefined, we propose a cluster division algorithm such that the destination nodes within each cluster can conduct data exchange locally with energy efficiency. Finally, simulation results demonstrate the effectiveness of the proposed scheme.

关键词： WIRELESS sensor networks coding theory DATA transmission systems DATA packets & packeting PROBABILITY theory ALGORITHMS

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A Mutual Algorithm for Optimizing Distributed Source coding in Wireless Sensor Networks

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第2期8卷 1-9页

作者： Abughalieh, Nashat Steenhaut, Kris Lemmens, Bart Nowe, Ann Vrije Univ Brussel Dept Elect & Informat ETRO B-1050 Brussels Belgium Erasmushogesch Brussel IWT B-1070 Brussels Belgium

Wireless Sensor Networks (WSNs) are composed of small wireless nodes equipped with sensors, a processor, and a radio communication unit, all normally powered by batteries. For most WSN applications, the network is expected to function for several months or years. In the common monitoring application scenario, adjacent nodes in a WSN often sense spatially correlated data. Suppressing this correlation can significantly improve the lifetime of the network. The maximum possible network data compression can be achieved using distributed source coding (DSC) techniques when nodes encode at Slepian-Wolf rates. This paper presents contributions to the lifetime optimization problem of WSNs in the form of two algorithms: the Updated-CMAX (UCMAX) power-aware routing algorithm to optimize the routing tree and the Rate Optimization (RO) algorithm to optimize the encoding rates of the nodes. The two algorithms combined offer a solution that maximizes the lifetime of a WSN measuring spatially correlated data. Simulations show that our proposed approach may significantly extend the lifetime of multihop WSNs with nodes that are observing correlated data.

关键词： DISTRIBUTED algorithms coding theory WIRELESS sensor networks DATA compression (Computer science) ROUTING algorithms RADIO (Medium)

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An Unbound Network coding for Extended IEEE 802.16j Multihop Relay Network

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第unknown期2012卷 1-15页

作者： Sukul, Adisak Chang, J. Morris Bhattarakosol, Pattarasinee Chulalongkorn Univ Dept Math Fac Sci Bangkok 10330 Thailand Iowa State Univ Dept Elect & Comp Engn Ames IA 50011 USA

IEEE 802.16j is an amendment to the IEEE 802.16 broadband wireless access standard to enable the operation of multihop relay stations (RSs). It aims to enhance the coverage, per user throughput of IEEE 802.16e. Comparing with a base station (BS), RS does not need a wireline backhaul and has much lower hardware complexity. Moreover, using RSs can significantly reduce the deployment cost of the system. Unfortunately, there are some tradeoffs in the case of multi-hop RSs. Subscriber stations (SSs), located in a long distance, are suffered from the bottleneck of multi-hop, throughput degradation, and increasing of end-to-end delay. This paper proposes a network coding-based relay scheme for multi-hop relay networks, called NC-BR. It allows RSs to combine two wireless backhaul transmissions into one using the network coding technique. This paper also proposes an improved OFDMA frame structure design for the multi-hop relay network. This technique provides higher utilization for the relay zone by reorganizing the RSs transmission sequence. The analysis and simulation results confirm that the proposed scheme can enhance the throughput gain up to 140% and reduce the end-to-end delay by up to 83%. The simulation results also show that the proposed scheme can reduce the jitter by up to 58%.

关键词： IEEE 802.16 (Standard) ELECTRIC relays WIRELESS sensor networks COMPUTER simulation NETWORK time delays coding theory COMPUTER input-output equipment

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An Adaptive Opportunistic Network coding Mechanism in Wireless Multimedia Sensor Networks

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INTERNATIONAL JOURNAL OF DISTRIBUTED SENSOR NETWORKS 2012年第12期8卷 1-13页

作者： Shen, Hang Bai, Guangwei Zhao, Lu Tang, Zhenmin Nanjing Univ Sci & Technol Minist Educ Key Lab Intelligent Percept & Syst High Dimens In Nanjing 210094 Jiangsu Peoples R China Nanjing Univ State Key Lab Novel Software Technol Nanjing 210093 Jiangsu Peoples R China Nanjing Univ Technol Dept Comp Sci & Technol Nanjing 210009 Jiangsu Peoples R China

The network coding technique is promising for improving the performance of video communication in wireless multimedia sensor networks. However, some special characteristics of existing wireless network coding mechanisms degrade the performance of video data delivery. This work begins with a thorough investigation and understanding of the performance limitations of existing wireless network coding mechanisms. On this basis, we propose an Adaptive Opportunistic Network coding mechanism (AONC) to improve the transmission quality of video stream in wireless multimedia sensor networks. First, we propose a novel asymmetric coding method to process the video data of different lengths. The aim is to improve data exchange gain. Second, we design an opportunistic forwarding strategy based on dynamic priority to ensure that packets have a better chance to be coded and transmitted, thus achieving much higher throughput. Finally, we present a traffic-aware data scheduling algorithm, working together with the above network coding mechanism, to reduce the loss of potential coding opportunities. Our simulation results demonstrate that, compared with the existing typical network coding mechanisms, AONC can greatly enhance video transmission quality and efficiently utilize bandwidth and energy resources.

关键词： coding theory WIRELESS sensor networks NETWORK performance (Telecommunication) DATA quality DYNAMICAL systems DATA packets & packeting DATA Traffic Management System (Computer system)

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