Characterization of the delay profile of systems employing random linear network coding is important for the reliable provision of broadcast services. Previous studies focused on network coding over large finite field...
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Characterization of the delay profile of systems employing random linear network coding is important for the reliable provision of broadcast services. Previous studies focused on network coding over large finite fields or developed Markov chains to model the delay distribution but did not look at the effect of transmission deadlines on the delay. In this paper, we consider generations of source packets that are encoded and transmitted over the erasure broadcast channel. The transmission of packets associated with a generation is taken to be deadline constrained, that is, the transmitter drops a generation and proceeds to the next one when a predetermined deadline expires. Closed-form expressions for the average number of required packet transmissions per generation are obtained in terms of the generation size, the field size, the erasure probability, and the deadline choice. An upper bound on the average decoding delay, which is tighter than previous bounds found in the literature, is also derived. Analysis shows that the proposed framework can be used to fine-tune the system parameters and ascertain that neither insufficient nor excessive amounts of packets are sent over the broadcast channel.
The encode-and-forward mechanism of network coding (NC) system, not only could provide increased network throughput, but also might get seriously vulnerable to pollution attacks. It has been an interesting and challen...
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The automatic modulation identification of a detected signal represents an essential task for an intelligent receiver and plays an important role in demodulating the intercepted signals for several communication syste...
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The automatic modulation identification of a detected signal represents an essential task for an intelligent receiver and plays an important role in demodulating the intercepted signals for several communication systems. In this study, the authors propose an efficient algorithm of superposed modulations identification dedicated for two-way relaying multiple-input multiple-output systems with physical-layer network coding (PLNC). The aim of this work is to identify a pair of sources modulations from the superposed constellation, when PLNC is applied. For this purpose, the authors use the higher order statistics-based features in conjunction with genetic algorithm and information theory as a features selection method and the random forests as a classifier. Simulations are provided to assess the accuracy of the proposed algorithm through the average probability of correct identification for different modulation scheme pairs. It is shown that the algorithm achieves high-modulation identification in acceptable signal-to-noise ratio level at different relay position.
In this study, a joint detection and generalised sum-product decoding algorithm for a two-way relay physical-layer network coding (PLNC) system in power line communication is proposed. Distinct from the existing works...
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In this study, a joint detection and generalised sum-product decoding algorithm for a two-way relay physical-layer network coding (PLNC) system in power line communication is proposed. Distinct from the existing works which mainly focused on separate or iterative PLNC detection and decoding, the proposed algorithm is a belief propagation-based joint PLNC detection and decoding algorithm, which integrates the PLNC, symbol detector and channel decoder together. The proposed algorithm is described by a joint factor graph, in which the detection nodes are connected to the factor graph of a generalised sum-product decoder. The PLNC demodulation is redesigned to make sure that the degree of each detection node in the joint factor graph is more than one. A low computational complexity solution of the proposed joint decoding algorithm based on the majority-logic algorithm is also proposed. The simulation results reveal the validity of the proposed algorithms.
Erasure networks can usually benefit from both spatial and temporal network coding, i.e., coding across packets both from different network edges as well as from different time slots. In this letter, we propose a join...
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Erasure networks can usually benefit from both spatial and temporal network coding, i.e., coding across packets both from different network edges as well as from different time slots. In this letter, we propose a joint spatial and temporal networking scheme with finite temporal coding length by extending the batch sparse (BATS) code proposed by Yang and Yeung. For the original BATS code, the batch size is usually set as the temporal coding length M. With the proposed spatial-temporal BATS code, a larger batch size kM, with k being the min-cut of the network, is used so that the spatial network coding can be applied together with temporal network coding. Simulation results show that the proposed scheme achieves significant throughput gain over the pure spatial or temporal network coding schemes.
Systematic wireless network coding has been proposed as a potential solution to solve the major drawback of high encoding/decoding complexities of random linear network coding and to increase the decoding capability. ...
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Systematic wireless network coding has been proposed as a potential solution to solve the major drawback of high encoding/decoding complexities of random linear network coding and to increase the decoding capability. However, the complete analysis of the decoding performance has not been fully derived. In this Letter, the authors derive closed-form expressions for the decoding probability under systematic network coding (SNC) over single-hop and multi-hop wireless networks. They validate the analysis by comparing simulation results. Their formulation provides a theoretical analysis for further understanding of the SNC and can be used to improve the current upper bound for the decoding probability.
The network coding mechanism has attracted much attention because of its advantage of enhanced network throughput which is a desirable characteristic especially in a multi-hop wireless network with limited link capaci...
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The network coding mechanism has attracted much attention because of its advantage of enhanced network throughput which is a desirable characteristic especially in a multi-hop wireless network with limited link capacity such as the device-to-device (D2D) communication network of 5G. COPE proposes to use the XOR-based network coding in the two-hop wireless network topology. For multi-hop wireless networks, the Distributed coding-Aware Routing (DCAR) mechanism was proposed, in which the coding conditions for two flows intersecting at an intermediate node are defined and the routing metric to improve the coding opportunity by preferring those routes with longer queues is designed. Because the routes with longer queues may increase the delay, DCAR is inefficient in delivering real-time multimedia traffic flows. In this paper, we propose a network coding-aware routing protocol for multi-hop wireless networks that enhances DCAR by considering traffic load distribution and link quality. From this, we can achieve higher network throughput and lower end-to-end delay at the same time for the proper delivery of time-sensitive data flow. The Qualnet-based simulation results show that our proposed scheme outperforms DCAR in terms of throughput and delay.
In this paper, we introduce 2 designs based on network coding (NC) for system-level throughput improvement in satellite systems. The first design is applied to the forward downlink of multibeam satellite systems using...
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In this letter, we use random linear network coding (RLNC) to deliver a two layered video sequence to two wireless subscribers such that a high-paying subscriber receives the highest quality and a low-paying subscribe...
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In this letter, we use random linear network coding (RLNC) to deliver a two layered video sequence to two wireless subscribers such that a high-paying subscriber receives the highest quality and a low-paying subscriber receives the basic quality. We first derive closed-form expressions for the probability of the low-paying subscriber intercepting sufficient coded packets to experience the highest video quality. We consider both feedback-aided and feedback-free transmissions. We propose a resource allocation framework that minimizes the intercept probability subject to deadline and subscribed video quality constraints. We show the tightness between the theoretical and simulation results, and illustrate the protection achieved by RLNC for subscription-based layered video delivery.
An opportunistic network coding (NC) scheme is proposed for the multi-relay-aided single-source single-destination network with transmission deadline. With the help of matrix analysis, the lower bound of decoding fail...
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An opportunistic network coding (NC) scheme is proposed for the multi-relay-aided single-source single-destination network with transmission deadline. With the help of matrix analysis, the lower bound of decoding failure probability of the proposed scheme is given. Simulation results show that: 1) the proposed scheme outperforms NC based on direct recoding scheme and the lower bound is tight when the source-to-relay channel erasure probability is relatively small and 2) given fixed network parameters, the optimal number of systematic packets delivered within deadline could be determined by using the derived bound for maximizing the throughput.
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