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IEEE Signal Processing and Communications Applications (SIU)

作者： Mustafa Yağımlı İbrahim Altunbaş Bilişim Teknolojileri Enstitüsü TÜBİTAK-BİLGEM Turkey Elektronik ve Haberleşme Müh. Bölümü İstanbul Teknik Üniversitesi Turkey

In this paper, two different physical layer network coding (PLNC) systems that apply antenna selection technique at the relay, consisting of two single-antenna terminals and a multi-antenna relay are proposed. The bound expressions of symbol error rate (SER) of the systems over frequency non-selective and slowly Rayleigh fading channels for M-PSK modulation are derived by using the moment generating function (MGF) method. In addition, Monte Carlo SER simulation results are given for both systems. According to the obtained theoretical and simulation results, diversity order of the systems is equal to the number of total antennas at the relay, and thus it is shown that error performance of the conventional PLNC system is significantly improved by the proposed systems. Also, SER performances of the proposed systems are compared with each other.

关键词： Signal to noise ratio network coding Physical layer Relays Transmitting antennas Phase shift keying

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Energy efficient MIMO two-way relay system with physical layer network coding

Energy efficient MIMO two-way relay system with physical lay...

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IEEE Conference on Wireless Communications and networking

作者： L. K. Saliya Jayasinghe N. Rajatheva M. Latva-aho Centre for Wireless Communications University of Oulu Oulu Finland

We investigate error performance and an optimum power allocation scheme for multiple-input multiple-output (MIMO) channel physical layer network coding (PNC) based two-way relay system. Zero forcing precoding technique is used at source nodes to facilitate PNC operations at the relay node. First, system error performance is investigated by introducing upper and lower bounds for BPSK modulation system. They are validated with numerical results and bounds provide accurate results at high SNR regime. Then, we consider sum rate maximization under a total power constraint to obtain the optimum power allocation scheme. Analytical solutions are derived and compared with other possible schemes, which are suboptimal. Numerical results confirm that the power allocation scheme provides the optimal solution for the achievable sum rate with the total available power and the relay position.

关键词： Relays MIMO Resource management Wireless communication network coding Antennas Bit error rate

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HopCaster: A network coding-Based Hop-by-Hop Reliable Multicast Protocol

HopCaster: A Network Coding-Based Hop-by-Hop Reliable Multic...

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IEEE Global Communications Conference

作者： Rami Halloush Hang Liu Lijun Dong Mingquan Wu Hayder Radha Dept. of Electrical & Computer Engineering Michigan State Univ. Interdigital Communications LLC King of Prussia Huawei Technologies Inc.

ISBN: (纸本)9781467309202

Intra-flow network coding (NC) is an innovative technique that has potential to improve multicast performance in wireless mesh networks (WMNs) by allowing intermediate forwarding nodes (FNs) to use coding and overhearing to reduce the number of required transmissions. However the benefits of the NC technology are limited unless there are protocols to exploit its capabilities. The existing intra-flow NC-based multicast protocols are all based upon the conventional end-to-end transport principle. By such a principle, intermediate FNs are unable to accurately determine the minimum number of coded packets they should transmit in order to ensure successful data delivery to the destinations, and hence redundant packets can be injected into the network, leading to performance degradation. Furthermore, the existing protocols cannot handle the bandwidth heterogeneity of multicast receivers very well. We argue that a receiver-driven hop-by-hop transport approach is more suitable for intra-flow NC and these two techniques can create synergy by enabling cooperation among the FNs. In this paper we propose HopCaster, a novel protocol that incorporates intra-flow NC with hop-by-hop transport to achieve high-throughput reliable multicast and to solve the heterogeneous receiver issue. It completely eliminates the need for estimating the number of coded packets to be transmitted by a FN and avoids transmission of redundant packets, as well as simplifies multicast management and congestion control. Moreover, HopCaster employs a cross-layer rate adaptation mechanism that optimizes radio transmission rate in hop-by-hop multicast by taking into consideration next-hop node population changes. Our evaluations show that HopCaster outperforms the existing NC-based reliable multicast protocol.

关键词： network coding Hop-by-hop Receiver driven Multicast Wireless mesh networks Multicast protocols Multicast Wireless mesh networks network coding Humulus Packet crosstalk protocols Numerical controls Receivers

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Impact of intra-flow network coding on the relay channel performance: An analytical study

Impact of intra-flow network coding on the relay channel per...

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IEEE International Conference on Wireless and Mobile Computing, networking And Communications (WiMob)

作者： Anya Apavatjrut Claire Goursaud Katia Jaffrès-Runser Jean-Marie Gorce Computer Engineering Chiang Mai University Chiang Mai Thailand Universite de Lyon INRIA/INS A-Lyon CITI-INRIA Lyon France Universite Federale Toulouse Midi-Pyrenees Toulouse Occitanie FR Université de Lyon INRIA / INSA-Lyon CITI-INRIA France

One of the most powerful ways to achieve transmission reliability over wireless links is to employ efficient coding techniques. This paper investigates the performance of a transmission over a relay channel where information is protected by two layers of coding. In the first layer, transmission reliability is ensured by fountain coding at the source. The second layer incorporates network coding at the relay node. Thus, fountain coded packets are re-encoded at the relay in order to increase packet diversity and reduce energy consumption. Performance of the transmission is measured by the total number of transmissions needed until the message is successfully decoded at the destination. We show through both analytical derivations and simulations that adding network coding capabilities at the relay optimizes system resource consumption. When the source uses a random linear fountain code, the proposed two-layer encoding becomes more powerful as it reduces the transmission rate over the direct link between the source and the destination.

关键词： Relays network coding Decoding Encoding Reliability Equations Protocols

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Compressive linear network coding for efficient data collection in wireless sensor networks

Compressive linear network coding for efficient data collect...

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European Signal Processing Conference (EUSIPCO)

作者： Francesca Bassi Chao Liu Lana Iwaza Michel Kieffer LSS-CNRS-SUPELEC University Paris Sud Gif-sur-Yvette France Institut Universitaire de France France LTCI-CNRS Télécom Paris Technology Paris France

We address the problem of data collection in a wireless sensor network. network coding is used for data delivery. The correlation between the measurements is exploited to recover the data at the sink, even in case of rank-deficient network matrix. The network coding operations are seen as lossy source compression, achieved by a finite-field random code generated during transmission. Decoding is performed using belief propagation on a factor graph which accounts for the correlation between the sensor measurements. Experimental results illustrate the performance of this technique for various field sizes and correlation levels.

关键词： network coding Wireless sensor networks Vectors Routing Correlation Decoding Joints

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Some further investigation on maximum throughput: Does network coding really help ?

Some further investigation on maximum throughput: Does netwo...

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International Teletraffic Congress, ITC 21

作者： Eric Gourdin Yuhui Wang Orange Laboratories CORE/TPN/TRM France Télécom France

network coding has been shown to be the solution that allows to reach the theoretical maximum throughput in a capacitated telecommunication network. It has also been shown to be a very appealing and practical alternative to routing-based approaches to send traffic from sources (servers) to terminals (clients) for many different applications. However, the initial theoretical claim of throughput benefit remains relatively unclear, mainly because the multicast throughput maximization problem is difficult to solve (it is closely related to the fractional Steiner tree packing problem which is NP-hard). In this paper, we show that these optimization problems are still tractable even for instances with a significant size (up to 50 nodes and 300 edges). We also propose and solve the multicast maximum throughput problem with an additional constraint on the number of multicast trees. We apply our algorithms on large sets of randomly generated instances, mainly based on bidirected graphs, because they are the most relevant to model fixed telecommunication infrastructures. The main result of our intensive experimental study is that, in practice, network coding does not increase throughput compared to traditional multicast. Instances showing a throughput gain can only be generated somewhat artificially by imposing some structure or trying to maximize the throughput gap. However, when we limit the number of multicast trees, then, most of the times, very significant throughput gaps appeared. Since management constraints often impose on network administrators a very limited use of multicast trees, network coding appears clearly as a very nice alternative for delivering content to customers.

关键词： Throughput network coding Steiner trees Routing Standards Computational modeling Encoding

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Improved HARQ based on network coding and its application in LTE

Improved HARQ based on network coding and its application in...

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IEEE Conference on Wireless Communications and networking

作者： Yidong Lang Dirk Wübben Armin Dekorsy Volker Braun Uwe Doetsch University of Brethemen Bremen Germany Alcatel-Lucent Bell Laboratories Stuttgart Germany

In this paper, a novel HARQ transmission scheme based on network coding is proposed for wireless unicast scenarios. Instead of retransmitting erroneous packets individually, a network coded packet constructed by the XOR of two erroneous packets is transmitted similar to network coding. In order to fully exploit the network coded packet in combination with the previously received erroneous packets, soft combining methods with respect to Chase Combing (CC) and Incremental Redundancy (IR) are developed. The expected throughput gain of 33% for one retransmission for the proposed solution compared to common HARQ transmission is confirmed by LTE link-level simulations.

关键词： Decoding Throughput Redundancy Signal to noise ratio network coding Convolutional codes Systematics

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Clustering Based Space-Time network coding

Clustering Based Space-Time Network Coding

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IEEE Global Communications Conference

作者： Wei Guan K. J. Ray Liu Department of Electrical and Computer Engineering University of Maryland

ISBN: (纸本)9781467309202

Many-to-one communication is a challenging problem in practice due to channel fading and multi-user interferences. In this work, a new protocol that leverages spatial diversity through space-time network coding is proposed. The N source nodes are first divided into K clusters, each having Q nodes, and the clusters send data successively in a time-division multiple access way. Each node behaves as a decode-and-forward relay to other clusters, and uses linear coding to combine the local symbol and the relayed symbols. To separate the multi-source signals, each node has a unique signature waveform, and linear decorrelator is used at the receivers. Both the exact Symbol Error Rate (SER) and the asymptotic SER at high signal-to-noise ratios of the M-ary phase-shift keying signal are studied then. It is shown that a diversity order of (N - Q + 1) can be achieved with a low transmission delay of K time slots, which is more bandwidth efficient than the existing protocols. Simulation results also justify the performance gains.

关键词： network coding Transport delay signal to noise ratios SAFETY EVALUATION REPORT Line of nodes Receivers Multi-user Interference INGRESS Quality factor time division multiple access linear codes

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network-coding based event diffusion for wireless networks using semi-broadcasting

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AD HOC networkS 2012年第6期10卷 871-885页

作者： Alnuweiri, H. Rebai, M. R. Beraldi, R. Univ Roma La Sapienza Comp & Syst Sci Dept Rome Italy Texas A&M Univ Qatar Doha Qatar

Publish/subscribe is a well known and powerful distributed programming paradigm with many potential applications. Publish/subscribe content dissemination techniques based on opportunistic networking and network coding-based epidemic routing are key techniques for optimizing network resources, simplifying network architecture, and providing a platform for realizing innovative networking applications and service. In this paper we consider the central problem of any pub/sub implementation, namely the problem of event dissemination, in the case of a wireless mesh network. We propose a new dissemination strategy based on the notion of semi-broadcast. In a semi-broadcast based protocol the actual content is disseminated in two phases. In the first phase only a fraction of the content is broadcasted (pushed) over the network and stored inside any node, whereas in the second phase the missed part is retried (pulled) on demand from other nodes. Thanks to network coding the partial content stored in each node at the end of the first phase is a set of random linear combinations over the whole content. This allows a very efficient recovery strategy as the missed part is found in nearby nodes with a high *** benefit of this approach is that only the interested subscribers, which can vary in number and position over time, can engage the pulling phase. We propose several protocols based on non-trivial forwarding mechanisms that employ network coding as a central tool for supporting adaptive event dissemination while exploiting the broadcast nature of wireless transmissions and guided to the semi-broadcast principle. We show a considerable enhancement in term of total flooding costs and full decoding rates by a self parameter control deployment during the dissemination procedure. (C) 2012 Elsevier B.V. All rights reserved.

关键词： network coding Semi-broadcast Publish/subscribe Event-dissemination Wireless

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Flexible and dynamic network coding for adaptive data transmission in DTNs

Flexible and dynamic network coding for adaptive data transm...

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International Wireless Communications and Mobile Computing Conference, IWCMC

作者： Milena Radenkovic Sameh Zakhary Department of Computer Science University of Nottingham Nottingham UK

Existing network coding approaches for Delay-Tolerant networks (DTNs) do not detect and adapt to congestion in the network. In this paper we describe CafNC (Congestion aware forwarding with network coding) that combines adaptive network coding and adaptive forwarding in DTNs. In CafNC each node learns the status of its neighbours, and their ego-networks in order to detect coding opportunities, and codes as long as the recipients can decode. Our flexible design allows CafNC to efficiently support multiple unicast flows, with dynamic traffic demands and dynamic senders and receivers. We evaluate CafNC with two real connectivity traces and a realistic P2P application, introducing congestion by increasing the number of unicast flows in the network. Our results show that CafNC improves the success ratio, delay and packet loss, as the number of flows grows in comparison to no coding and hub-based static coding, while at the same time achieving efficient utilisation of network resources. We also show that static coding misses a number of coding opportunities and increases packet loss rates at times of increased congestion.

关键词： network coding Encoding Delay Adaptive systems Protocols

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