We investigate the potential gains of Physical-Layer network coding (PLNC) in multi-hop wireless networks. Physical-Layer network coding was first introduced as a solution to increase the throughput of a two-way relay...
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ISBN:
(纸本)9781509053360
We investigate the potential gains of Physical-Layer network coding (PLNC) in multi-hop wireless networks. Physical-Layer network coding was first introduced as a solution to increase the throughput of a two-way relay channel communication. Unlike most wireless communications techniques which try to avoid collisions, PLNC allows two simultaneous transmissions to a common receiver. Such transmitted messages are summed at signal level and then decoded at packet level. In basic topologies, Physical-Layer network coding has been shown to significantly enhance the throughput performance compared to classical communications. However, the impact of PLNC in large multi-hop networks remains an open question. We therefore exploit Linear Programming to evaluate the impact of this paradigm in large realistic radio deployments. Our numerical results show that PLNC can increase the throughput in large multi-hop topologies by 30%. Such gains set theoretical benchmarks for designing new access methods and routing protocols to efficiently exploit the Physical-Layer network coding concept.
Satellite on-board network switch technology is one of the key technologies of satellite network system. Orthogonal Frequency Division Multiplexing has high spectrum utilization and can outperform anti-multipath fadin...
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ISBN:
(纸本)9781467389792
Satellite on-board network switch technology is one of the key technologies of satellite network system. Orthogonal Frequency Division Multiplexing has high spectrum utilization and can outperform anti-multipath fading ability efficiently. Each sub-carrier wave of OFDM signal can be used independently;therefore satellite on-board OFDM switching system has received widespread attention. Satellite network coding, one of the heated research fields of satellite network system, becomes the core of satellite switching technologies gradually. This article will expound the advantages of these two technologies and design a satellite on-board OFDM switching system, which has a greater channel capacity. At last, a simulation of the system demonstrates the theory can be realized.
The theory of network coding (NC) has been studied in recent years and makes significant benefits to the performance of Transmission Control Protocol (TCP) in lossy and/or dynamic wireless networks. However, due to th...
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ISBN:
(纸本)9781509063529
The theory of network coding (NC) has been studied in recent years and makes significant benefits to the performance of Transmission Control Protocol (TCP) in lossy and/or dynamic wireless networks. However, due to the asynchronous packet transmission between the transport layer and the network coding layer of the protocol stack, sliding window mechanism with a fixed size of coding window may lead to network delay and thus the performance gain of network coding cannot be fully exploited. In this paper, we propose to use an advanced architecture named Encoding Block Manager (EBM) to optimize packet encoding and scheduling process in a parallel manner. Further, a dynamic encoding algorithm is introduced in EBM to adjust the size of encoding block adaptively according to the Round Trip Time (RTT). To demonstrate the performance of EBM, simulation works are implemented with network Simulation (NS) 2. In comparison with TCP/NC, the results certified the effectiveness of the system.
In this paper, we present an asynchronous analog network coding (AANC) scheme for multiuser cooperative communications. In particular, we consider a relay network comprised of multiple sources and one relay. With conv...
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ISBN:
(纸本)9781509041831
In this paper, we present an asynchronous analog network coding (AANC) scheme for multiuser cooperative communications. In particular, we consider a relay network comprised of multiple sources and one relay. With conventional analog network coding, i. e., synchronous analog network coding (SANC), perfect timing synchronization is assumed. In contrast, in AANC, the signals from the sources arrive at the relay and destination with different time delays. Then the relay amplifies the received asynchronous combination of the transmitted signals and forwards it to the destination. We present a simple decoding strategy at the destination and examine the diversity order by investigating the asymptotic performance at a high signal to noise ratio. Our results show that AANC achieves a greater diversity order compared to that of SANC with the same linear decoding complexity. In addition, we present the Viterbi decoding for AANC and use simulations to compare its performance with that of SANC with maximum likelihhood decoding. We show that AANC has a better symbol error rate performance compared to that of SANC.
We propose a piggybacking scheme for network coding where strong source inputs piggyback the weaker ones, a scheme necessary and sufficient to achieve the cut-set upper bound at high/low-snr regime, a new asymptotical...
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ISBN:
(纸本)9781509050192
We propose a piggybacking scheme for network coding where strong source inputs piggyback the weaker ones, a scheme necessary and sufficient to achieve the cut-set upper bound at high/low-snr regime, a new asymptotically optimal operational regime for the multihop Amplify and Forward (AF) networks.
Relay selection and network coding are two main factors for improving cooperative networks. Employing all the relays without any relay selection in the network increase power consumption and cost to transfer data. Sel...
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ISBN:
(纸本)9781538631324
Relay selection and network coding are two main factors for improving cooperative networks. Employing all the relays without any relay selection in the network increase power consumption and cost to transfer data. Selection of one or more relays decreases the power consumption, reduces the interference and complexity. network coding increase throughput and decrease error rate. This research proposes a new method for relay selection in two-way relay channel with considering network coding. This choice is based on absolute value of the log-likelihood ratio(LLR) of the received signal at each relay node. The proposed scheme is derived for BPSK modulation. System performance is evaluated by numerical simulations and compared with Max-Min relay selection method. The proposed method is evaluated by bit error rate (BER) simulated curves for AWGN channels and compared to Max-Min relay selection method.
We propose an anti-occlusion indoor visible light system which utilizes the physical layer network coding (PNC) as relay scheme. Comparing with traditional relay scheme, the PNC relay scheme improves the throughput ra...
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ISBN:
(纸本)9781943580347
We propose an anti-occlusion indoor visible light system which utilizes the physical layer network coding (PNC) as relay scheme. Comparing with traditional relay scheme, the PNC relay scheme improves the throughput rate by 50%.
network coding is a technique used to improve both wired and wireless networks' throughput and provide reliable transmission. In network coding, original data packets can be encoded to an infinite number of coded ...
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ISBN:
(纸本)9781509029914
network coding is a technique used to improve both wired and wireless networks' throughput and provide reliable transmission. In network coding, original data packets can be encoded to an infinite number of coded packets. A subset of these coded packets is sufficient to decode the coded packets and retrieve the original data. In addition to providing reliable data transmission, network coding can be used as a lightweight security mechanism to protect data against eavesdroppers. An eavesdropper is not able to decode coded packets and retrieve original data unless it has access to a sufficient number of coded packets. In a data transmission application, transmitting more redundant packets increases the chance of delivering a sufficient number of coded packets to the destination. As a result, this increases the reliability of the data transmission. However, more redundant transmissions make the system more vulnerable to eavesdropper attacks because there is a higher chance that an eavesdropper will receive enough coded packets. In this work, we study network coding to provide reliable and secure data transmission schemes by performing a trade-off between the security and reliability of the data transmission. We formulate the problem as a mixed integer and linear programming problem, and we propose a linear programming approximation to solve it. We study the performance of our proposed methods through extensive simulations.
We study an uplink distributed multiple-input multiple-output (D-MIMO) system, where multiple users are served by multiple base stations (BSs) connected to a common central unit (CU) via independent backhaul links. We...
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ISBN:
(纸本)9781538645024
We study an uplink distributed multiple-input multiple-output (D-MIMO) system, where multiple users are served by multiple base stations (BSs) connected to a common central unit (CU) via independent backhaul links. We propose an optimized signal-space aligned network coding transceiver scheme for sum-rate maximization. In the scheme, the signal alignment pattern and computed message combinations are determined by a carefully designed indicator matrix. Linear precoding operations at users are applied to realize the signal-space alignment. The aligned spatial streams at BSs are used to generate message combinations. We jointly optimize the alignment pattern and linear precoding operations to achieve a higher sum rate. Numerical results demonstrate the superiority of our proposed scheme over other benchmark schemes.
Delay linear network coding (DLNC) is the problem of network coding, in which coding operation takes time. A coherent DLNC network, where coding operation at each node takes 1 unit time, can be modeled as a linear tim...
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ISBN:
(纸本)9781509015733
Delay linear network coding (DLNC) is the problem of network coding, in which coding operation takes time. A coherent DLNC network, where coding operation at each node takes 1 unit time, can be modeled as a linear time invariant (LTI) system. Based on the Gauss Jordan elimination, we develop an algorithm to reconstruct source processes and introduce new concepts, which are decoding delay and transmission rate. The network error control problem in such networks can be done by extending the classical network error-correcting code (NEC). We construct a DLNC based linear operation channel (LOC) and apply the distance measure proposed in the previous works to our LOC. It turns out that extension of classical NEC works well for the case of DLNC. We also develop a codebook design algorithm, which achieves maximum possible size.
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