In practical asynchronous physical-layer network coding (PNC) systems, the symbols from multiple transmitters to a common receiver may be misaligned. The good performance of an asynchronous PNC decoder hinges on accur...
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ISBN:
(纸本)9781467389990
In practical asynchronous physical-layer network coding (PNC) systems, the symbols from multiple transmitters to a common receiver may be misaligned. The good performance of an asynchronous PNC decoder hinges on accurate estimation of the symbol misalignment. This paper puts forth an optimal symbol misalignment estimator that considerably improves the estimation accuracy over prior schemes. Our scheme makes use of double baud-rate sampling of the received preambles consisting of Zadoff-Chu (ZC) sequences used by different transmitters. The sampling process is information-lossless because the double baud-rate samples capture all the information embedded in the continuous-time signal shaped by the assumed root-raised-cosine (RRC) pulse. The estimation consists of three steps: (i) cross-correlation of the double baud-rate samples with "interpolated double baud-rate ZC sequences";(ii) noise whitening;(iii) maximum likelihood (ML) estimation of the symbol misalignment. Extensive simulations show that the mean-square-error (MSE) performance of our estimator is superior to that of the baudrate estimator - e.g., for the RRC pulse with roll-off factor, our double baud-rate estimator yields improvement of dB over the baud-rate estimator. Furthermore, our double baudrate estimator yields square errors of less than with probability when the SNR is dB in both AWGN and Rayleigh fading channels.
Delay Tolerant network(DTN) is widely applied to the situation that difficult to deploy infrastructure. It has the characteristics of nodes distributed sparsely, connect unstably, large delay and high bit error rate. ...
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ISBN:
(纸本)9781509038237;9781509038220
Delay Tolerant network(DTN) is widely applied to the situation that difficult to deploy infrastructure. It has the characteristics of nodes distributed sparsely, connect unstably, large delay and high bit error rate. These characteristics of DTN, lead to the data efficient transmission encountered a certain challenge. network coding is proposed to improve network throughput, balance network load and improve network bandwidth utilization. The key idea is that nodes in the network not only participate in message forwarding, but also take part in data encoding processing. It introduced the idea of network coding into the DTN routing strategy greatly enhance the success rate of packet delivery and network delay performance, make up for the high delay, high bit error rate in DTN and so on. This paper summarizes the routing strategies based on network coding in DTN environment, and qualitatively compares those routing strategies. The future research direction is pointed out through the comparative analysis of the existing research.
Multipath routing has been proved to improve the reliability and throughput of data transmission in ad-hoc networks. However, in FANETs, due to frequent link failures and rapid changes in network topology, it is diffi...
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ISBN:
(纸本)9781538611074
Multipath routing has been proved to improve the reliability and throughput of data transmission in ad-hoc networks. However, in FANETs, due to frequent link failures and rapid changes in network topology, it is difficult to dynamically build these paths and the maintenance overhead is also unacceptable. Given that network encoding can take advantage of the broadcast nature of the wireless channel to improve the transmission performance of multipath routing, we proposed a multipath routing scheme NC-OLSR for FANETS based on the OLSR (Optimized Link State Routing) protocol. NC-OLSR adopts OLSR to create a hybrid multipath selection model based on neighbor nodes' link quality. Moreover, a network coding based data transmission scheme is designed for each end-to-end data transmission task. Thus, NC-OLSR reduces the local constraints which cannot be avoided in the single OLSR or multipath routing scheme. Experimental results show that NC-OLSR can significantly improve the data delivery ratio and improve the transmission efficiency.
network coding (NC) is a forward-looking technology of coding technology, which can rapidly improve the network throughput and bandwidth available in Mobile Ad hoc network (MANET). Sliding window network coding is an ...
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ISBN:
(纸本)9781538611074
network coding (NC) is a forward-looking technology of coding technology, which can rapidly improve the network throughput and bandwidth available in Mobile Ad hoc network (MANET). Sliding window network coding is an improved encoding of network coding, which increases the network throughput of TCP to MANETs by increasing the sliding mechanism. In this paper, we propose a Variable Length Sliding Window network coding algorithm in MANETs (VLSWNC). The performance of the VLSWNC is experiments studied by using NS2 and evaluated in terms of the network throughput, packet loss probability, and decoding delay when data packet is transmitted. Simulation results show that VLSWNC can significantly improve network throughput and achieve better network performance.
In wireless multi-relay cooperative communication,the relay node forwards the received packets to the source node and destination node to complete the two-way collaborative ***,the p
ISBN:
(纸本)9781467389808
In wireless multi-relay cooperative communication,the relay node forwards the received packets to the source node and destination node to complete the two-way collaborative ***,the p
The individual applications of network coded opportunistic routing and successive interference cancellation have been proven with significant improvement on throughput performance of wireless multi-hop networks, but t...
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ISBN:
(纸本)9781538632215
The individual applications of network coded opportunistic routing and successive interference cancellation have been proven with significant improvement on throughput performance of wireless multi-hop networks, but there lacks practical optimization on their combination application. Based on a T-DMA system, this paper models the throughput maximization as network utility function maximization problem. Applying Lagrangian dual decomposition theory and sub-gradient method, the network utility maximization problem is decomposed into source rate control, routing with NCOR and scheduling under SIC. These three subproblems are solved independently and linked by queue length to achieve coordinating and solve joint maximizing problem of network throughput. To provide practical optimization, this paper implements the joint optimization framework with low-overhead distributed algorithm and verifies its performance through experiments. The numeral results show that the cross-layer combination of NCOR and SIC achieves significant effect on enhancing throughput, improving efficiency and reducing slot overhead, compared to cross-layer or layered models which only consider network coding.
network coding is a potential method that numerous investigators have move forwarded due to its significant advantages to enhance the proficiency of data communication. In this work, utilize simulations to assess the ...
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ISBN:
(纸本)9781538619780
network coding is a potential method that numerous investigators have move forwarded due to its significant advantages to enhance the proficiency of data communication. In this work, utilize simulations to assess the execution of various network topologies employing network coding. By contrasting the results of network and without network coding, it insists that network coding can improve the throughput, end-to-end delays, Packet Delivery Rate (PDR) and consistency. This paper presents the comparative performance analysis of network coding such as, XOR, LNC, and RLNC. The results demonstrates the XOR technique has attractive outcomes and can improve the real time performance metrics i.e.;throughput, end-to-end delay and PDR by substantial limitations. The analysis has been carried out based on packet size and also number of packets to be transmitted. Results illustrates that the network coding facilitate in dependence between networks.
This paper studies the throughput performance of a two-way energy harvesting relaying system. network coding and Energy Harvesting are promising techniques that can improve the transmission efficiency and the energy e...
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ISBN:
(纸本)9781467389990
This paper studies the throughput performance of a two-way energy harvesting relaying system. network coding and Energy Harvesting are promising techniques that can improve the transmission efficiency and the energy efficiency of wireless systems, respectively. In particular, we focus on the energy harvesting system with the power splitting-based relaying (PSR) protocol, and consider both the amplify-and-forward (AF) relaying and decode-and-forward (DF) relaying methods for the network coding. We successfully derive the expressions for both the outage probability and the system throughput for each case. It can be shown that DF relaying system outperforms AF relaying system in terms of both the outage probability and the throughput. Furthermore, simulations show that the throughput gain brought by network coding highly depends on the signal-to-noise ratio (SNR) at the receiver. The throughput gain can he up to 33% in the high SNR region.
For traditional routing model in wireless sensor networks(WSN), the function of intermediate nodes is storage and forwarding. Due to the limitation of WSN in energy, capability of communication, computing and the capa...
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ISBN:
(纸本)9781509064151;9781509064144
For traditional routing model in wireless sensor networks(WSN), the function of intermediate nodes is storage and forwarding. Due to the limitation of WSN in energy, capability of communication, computing and the capability of storage, it is difficult for nodes to communicate. Existing researches show that using network coding in WSN can enhance throughput and the security transmission of network, and reduce the energy consumption of nodes [1]. This paper chooses a typical TEEN protocol as the research object of network coding. We attempt to employ network coding to achieve the improvement on throughput of WSN and communication performance, and decrease the energy consumption of sensor nodes. Based on these points, this paper proposes to create network coding opportunities on cluster head nodes in TEEN protocol by utilizing the advantages of opposite links, and a new network coding model basing on TEEN(NCTEEN). The results of simulations show that NCTEEN model has better performance than TEEN in terms of throughput and energy consumption. To be specific, the throughput and performance of network are improved and the energy consumption in cluster head nodes is reduced.
This paper considers a problem of anonymous transmission against eavesdropping and jamming in coherent network coding. We propose an information-theoretical message unlinkability scheme based on coset coding. We show ...
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