The wide availability of power distribution cables provides an interesting no-new-wires communication channel. However, its electrical characteristics make it a harsh environment for the data transmission purpose and ...
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The wide availability of power distribution cables provides an interesting no-new-wires communication channel. However, its electrical characteristics make it a harsh environment for the data transmission purpose and prevent the deployment of services with high reliability requirements. This paper proposes and implements an OSI-Layer2 network coding-based cooperative scheme with the aim of improving communication reliability in indoor narrowband powerline channels. The proposed scheme uses random linear network coding with a sliding window and relaying. We use network coding to replace the retransmissions triggered by legacy subsequent repeat request (ARQ) schemes. We evaluate the performance of our approach in terms of throughput and delay. Regarding the throughput achieved in harsh environments, we show that our scheme often more than doubles the throughput of existing legacy ARQ schemes. At the same time, and even under the large variation of traffic characteristics, it is shown that the delay is likely to be upper bounded by a few seconds, a bound that cannot be guaranteed in other existing transmission techniques.
We evaluate the performance of a network-coded cooperative secondary network in a cognitive radio system under spectrum sharing constraints. The secondary network is composed of multiple sources that cooperate to tran...
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We evaluate the performance of a network-coded cooperative secondary network in a cognitive radio system under spectrum sharing constraints. The secondary network is composed of multiple sources that cooperate to transmit their own information to a common secondary destination. The outage probability is analysed under a given maximum interference constraint set by the primary network as well as to the maximum transmit power limit of the secondary sources. Moreover, we also obtain a closed-form equation for the epsilon-outage capacity, that is, the maximum information rate achieved by the secondary sources given a target outage probability. Also, we resort to the Dinkelbach algorithm in order to find the optimum number of parity packets that maximises the epsilon-outage capacity. The influence of the number of source nodes and another system parameters in the secondary's performance is also evaluated, and we show through theoretical and numerical results that cooperative communication with network coding can provide significant gains in terms of outage probability and diversity order when compared with non-cooperative or traditional cooperative. Copyright (C) 2015 John Wiley & Sons, Ltd.
In Wireless Body Area networks(WBANs), the tradeoff between network throughput and energy efficiency remains a key challenge. Most current transmission schemes try to cope with the challenge from the perspective of ge...
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In Wireless Body Area networks(WBANs), the tradeoff between network throughput and energy efficiency remains a key challenge. Most current transmission schemes try to cope with the challenge from the perspective of general Wireless Sensor networks (WSNs), which may not take the peculiarities of WBAN channels into account. In this paper, we take advantage of the correlation of on-body channels in walking scenarios to achieve a better tradeoff between throughput and energy consumption. We first analyze the characteristics of on-body channels based on realistic channel gain datasets, which are collected by our customized wireless transceivers in walking scenarios. The analytical results confirm the rationale of our newly proposed transmission scheme A3NC, which explores the combination of the aggregative allocation (AA) mechanism in MAC layer and the Analog network coding (ANC) technique in PHY layer. Both theoretical analyses and simulation results show that the A3NC scheme achieves significant improvement in upload throughput and energy efficiency, compared to the conventional approaches.
Vehicular networks, as a significant technology in intelligent transportation systems, improve the convenience, efficiency, and safety of driving in smart cities. However, because of the high velocity, the frequent to...
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Vehicular networks, as a significant technology in intelligent transportation systems, improve the convenience, efficiency, and safety of driving in smart cities. However, because of the high velocity, the frequent topology change, and the limited bandwidth, it is difficult to efficiently propagate data in vehicular networks. This paper proposes a data dissemination scheme based on fuzzy logic and network coding for vehicular networks, named SFN. It uses fuzzy logic to compute a transmission ability for each vehicle by comprehensively considering the effects of three factors: the velocity change rate, the velocity optimization degree, and the channel quality. Then, two nodes with high abilities are selected as primary backbone and slave backbone in every road segment, which propagate data to other vehicles in this segment and forward them to the backbones in the next segment. The backbone network helps to increase the delivery ratio and avoid invalid transmissions. Additionally, network coding is utilized to reduce transmission overhead and accelerate data retransmission in interbackb one forwarding and intrasegment broadcasting. Experiments show that, compared with existing schemes, SFN has a high delivery ratio and a short dissemination delay, while the backbone network keeps high reliability.
In mobile wireless sensor networks, linear network coding has been shown to improve the performance of network throughput and reduce delay. However, the linear dependence of coded packets caused by linear network codi...
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In mobile wireless sensor networks, linear network coding has been shown to improve the performance of network throughput and reduce delay. However, the linear dependence of coded packets caused by linear network coding will result in significant instability of the entire network during data transmission. Moreover, current linear network coding schemes do not distinguish between the real-time requirements of different packets. To solve the above problems, a weighted Vandermonde echelon fast coding scheme is proposed based on an analysis of various coding schemes such as random and linear network coding. Weighted Vandermonde echelon fast coding scheme can reduce the dependence problem of the network coding matrix and distinguish between different packet priorities. The accuracy of the proposed weighted Vandermonde echelon fast coding method is investigated through a theoretical analysis and then its outstanding delivery performance is verified through discrete event simulation experiments.
An improved energy-efficient compressed network coding method is proposed for the data communication in the wireless sensor networks (WSNs). In the method, the compressed sensing and network coding are jointly used to...
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An improved energy-efficient compressed network coding method is proposed for the data communication in the wireless sensor networks (WSNs). In the method, the compressed sensing and network coding are jointly used to improve the energy efficiency, and the two-hop neighbor information is employed to choose the next hop to further reduce the number of the transmissions. Moreover, a new packet format is designed to facilitate the intermediate node selection. To theoretically verify the efficiency of the proposed method, the expressions for the number of the transmissions and receptions are derived. Simulation results show that, the proposed method has higher energy efficiency compared with the available schemes, and it only requires a few packets to reconstruct measurements with reasonable quality.
In this paper, we focus on the encoding/decoding designing and its performance analysis for a two-way relaying system. In the two-way relaying system, two source points broadcast their information to a group of relays...
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In this paper, we focus on the encoding/decoding designing and its performance analysis for a two-way relaying system. In the two-way relaying system, two source points broadcast their information to a group of relays in different phases. The relays lightly decode the received signals from them to estimate the information of two source points. An exclusive OR (XOR)-based network coding is then performed by each relay over two estimated binary sequences even though they contain errors. Each relay re-encodes the XORed information using concatenated convolutional codes and forwards the coded information to two source points. A joint decoding scheme which utilizes the correlation knowledge among the relayed information is proposed to reduce the energy consumption and to achieve well performance. Simulation results show that the proposed scheme can signi cantly reduce the energy consumptions and can achieve full diversity order.
Due to the advantages of low transmit power consumption, high spectral efficiency and extended system coverage, Device-to-Device (D2D) communication has drawn explosive attention in wireless communication field. Consi...
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Due to the advantages of low transmit power consumption, high spectral efficiency and extended system coverage, Device-to-Device (D2D) communication has drawn explosive attention in wireless communication field. Considering that intra-cell interference caused between cellular signals and D2D signals, in this paper, a network coding-based D2D relay cooperative transmission algorithm is proposed. Under D2D single-hop relay transmission mode, cellular interfering signals can be regarded as useful signals to code with D2D signals at D2D relay node. Using cellular interfering signals and network coded signals, D2D receiver restores the D2D signals to achieve the effect of interference suppression. Theoretical analysis shows that, compared with Amplify-and-forward (AF) mode and Decode-and-forward (DF) mode, the proposed algorithm can dramatically increase the link achievable rate. Furthermore, simulation experiment verifies that by employing the proposed algorithm, the interference signals in D2D communication can be eliminated effectively, and meanwhile the symbol error rate (SER) performance can be improved.
Data dissemination in vehicular ad hoc networks has been an interesting research topic since rising applications can be run and served based on the success and efficiency of data dissemination in vehicular ad hoc netw...
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Data dissemination in vehicular ad hoc networks has been an interesting research topic since rising applications can be run and served based on the success and efficiency of data dissemination in vehicular ad hoc networks. However, the volatile vehicle density, the highly dynamic topologies, and the packet lossy nature of the vehicular wireless communications pose real challenges for vehicular ad hoc networks to achieve high-speed content downloading and efficient resource utilization. In this work, we design a collision-free distributed relay selection method, by jointly considering the geographical locations, channel conditions, moving velocities, and packets receiving statuses of vehicles, to combat the mobility and lossy channel property of vehicular ad hoc networks. Moreover, we adopt the instantly decodable network coding for the selected relay vehicle to retransmit packets which were lost in the original transmission, resulting significant improvements in both network throughput and transmission delay. Simulation results show that the proposed strategy effectively reduces the delay of data dissemination in highway scenarios and improves the downloading rate, as well as the resource utilization of wireless channels.
In this work, we study efficient scheduling with network coding in a scalable video coding (SVC) multicast system. Transmission consists of two stages. The original SVC packets are multicasted by the server in the fir...
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In this work, we study efficient scheduling with network coding in a scalable video coding (SVC) multicast system. Transmission consists of two stages. The original SVC packets are multicasted by the server in the first stage and the lost packets are retransmitted in the second stage. With deadline constraint, the consumer can be only satisfied when the requested packets are received before expiration. Further, the hierarchical encoding architecture of SVC introduces extra decoding delay which poses a challenge for providing acceptable reconstructed video quality. To solve these problems, instantly decodable network coding is applied for reducing the decoding delay, and a novel packet weighted policy is designed to better describe the contribution a packet can make in upgrading the recovered video quality. Finally, an online packet scheduling algorithm based on the maximal weighted clique is proposed to improve the delay, deadline miss ratio and users' experience. Multiple characteristics of SVC packets, such as the packet utility, the slack time and the number of undelivered/wanted packets, are jointly considered. Simulation results prove that the proposed algorithm requires fewer retransmissions and achieves lower deadline miss ratio. Moreover, the algorithm enjoys fine recovery video quality and provides high user satisfaction.
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