In this letter, we derive the closed-form analytical expressions for the exact Bit Error Rate (BER) of physicallayernetworkcoding (PNC) systems considering M-ary Quadrature Amplitude Modulation (M-QAM) schemes in O...
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In this letter, we derive the closed-form analytical expressions for the exact Bit Error Rate (BER) of physicallayernetworkcoding (PNC) systems considering M-ary Quadrature Amplitude Modulation (M-QAM) schemes in Orthogonal Frequency Division Multiplexing (OFDM) systems. We validate our results with Monte Carlo simulations.
The concept of physical-layer network coding (PNC) was proposed in 2006 for application in wireless networks. Since then it has developed into a subfield of networkcoding with wide implications. The basic idea of PNC...
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The concept of physical-layer network coding (PNC) was proposed in 2006 for application in wireless networks. Since then it has developed into a subfield of networkcoding with wide implications. The basic idea of PNC is to exploit the mixing of signals that occurs naturally when electromagnetic (EM) waves are superimposed on one another. In particular, at a receiver, the simultaneous transmissions by several transmitters result in the reception of a weighted sum of the signals. This weighted sum is a form of networkcoding operation by itself. Alternatively, the received signal could be transformed and mapped to other forms of networkcoding. Exploiting these facts turns out to have profound and fundamental ramifications. Subsequent works by various researchers have led to many new results in the domains of (1) wireless communication, (2) information theory, and (3) wireless networking. The purpose of this paper is fourfold. First, we give a brief tutorial on the basic concept of PNC. Second, we survey and discuss recent key results in the three aforementioned areas. Third, we examine a critical issue in PNC: synchronization. It has been a common belief that PNC requires tight synchronization. Recent results suggest, however, that PNC may actually benefit from asynchrony. Fourth, we propose that PNC is not just for wireless networks;it can also be useful in optical networks. We provide an example showing that the throughput of a passive optical network (PON) could potentially be raised by 100% with PNC. (C) 2012 Elsevier B.V. All rights reserved.
In this study, we develop a physical-layer network coding based throughput-optimal transmission scheduling policy, which we call networkcoding aware maximum differential backlog (NCMDB), and demonstrate its throughpu...
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In this study, we develop a physical-layer network coding based throughput-optimal transmission scheduling policy, which we call networkcoding aware maximum differential backlog (NCMDB), and demonstrate its throughput optimality. As the proposed policy requires an NP-hard network-wide centralized algorithm to determine the optimal transmission schedule, we propose a distributed NCMDB based on link prioritization (D-NCMDB) as a lower bound approach. We further propose a bidirectionality-aware route establishment scheme for the best application of the NCMDB and D-NCMDB policies. Simulations confirm that compared to the signal-to-interference-based interference avoidance transmission approach and random maximal physical-layer network coding approach, the proposed D-NCMDB scheme offers 48% and 27% increased throughput, 78% and 63% reduced access delay, and 80% and 20% enlarged stability, respectively. The proposed distributed transmission scheduling scheme can be employed in future communication networks in which both the number of nodes and the amount of interference increase exponentially.
In this paper, we propose an enhanced low-complexity binary physical-layer network coding (PNC) based decoding scheme for random access systems with binary phase-shift keying modulation to improve the system throughpu...
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In this paper, we propose an enhanced low-complexity binary physical-layer network coding (PNC) based decoding scheme for random access systems with binary phase-shift keying modulation to improve the system throughput. In the proposed scheme, the linear combinations of collided users' messages in each time slot are first obtained by exploiting a low-complexity PNC decoding scheme. Based on the decoded linear combinations within a MAC frame, we then propose an enhanced message-level successive interference cancellation algorithm to recover more users' messages. We propose an analytical framework for the PNC-based decoding scheme and derive a tight approximation of the system throughput for the proposed scheme. Subsequently, the number of repeated transmissions of a message, i.e., the number of replicas transmitted by each user, is optimized to further improve the system throughput and energy efficiency. Interestingly, the optimization results show that the optimal number of replicas for maximizing the energy efficiency is a constant for all offered loads. On the other hand, the optimal number of replicas that maximizes the system throughput decreases as the offered load increases. Numerical results show that the derived analytical results closely match with the simulation results. Furthermore, the proposed scheme achieves a considerable throughput improvement, compared to the CRDSA++ scheme.
To improve the bit error rate (BER) performance of physical-layer network coding (PNC) in asymmetric two-way relay channels (TWRC), in this paper, we study a new PNC scheme named bi-quadrature physical-layernetwork c...
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To improve the bit error rate (BER) performance of physical-layer network coding (PNC) in asymmetric two-way relay channels (TWRC), in this paper, we study a new PNC scheme named bi-quadrature physical-layer network coding (BQ-PNC) for Rayleigh flat fading TWRC. In BQ-PNC scheme, the two users employ quadrature carriers and the relay node use quadrature combining rather than XOR which is very common in other PNC schemes. We give the BER analysis of BQ-PNC and simulate the performance. Theoretical and simulation results show that the proposed scheme can significantly enhanced the BER performance, either in symmetric or asymmetric cases. Especially for uplink asymmetric TWRC, BQ-PNC can provide more than 4 dB gain compared with PNC scheme.
To improve the limited-bandwidth in shallow underwater acoustic communication, we propose to apply the physical-layer network coding (PNC) to this communication system. This paper analyzes the model of shallow underwa...
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ISBN:
(纸本)9789811065712;9789811065705
To improve the limited-bandwidth in shallow underwater acoustic communication, we propose to apply the physical-layer network coding (PNC) to this communication system. This paper analyzes the model of shallow underwater acoustic channel - "Ray Model" and uses the adaptive equalization technique to eliminate the inter-symbol interference (ISI). Besides, we also study the principle of PNC and research the demodulation and mapping scheme in relay node. Finally, we combine the channel model and PNC technique in two-way relay communication (TWRC) system. The performance simulation of PNC is compared with the traditional multi-hop scheme and networkcoding (NC) scheme. The result shows that PNC scheme can improve the throughput of system but do not increase the bit error rate (BER) in the shallow underwater acoustic communication. It provides a new research direction for shallow underwater acoustic communication, and also expands a new field for PNC applications.
We propose a new linear physical-layer network coding and information combining scheme for the K-user fading multiple-access relay network (MARN), which consists of K users, one relay and one destination. The relay an...
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ISBN:
(纸本)9781509013289
We propose a new linear physical-layer network coding and information combining scheme for the K-user fading multiple-access relay network (MARN), which consists of K users, one relay and one destination. The relay and the destination are connected via a rate-constraint backhaul link. In the proposed scheme, the K users transmit signals simultaneously. The relay and the destination receive the superimposed signals distorted by fading and noise. The relay reconstructs L linear combinations of the K users' messages, referred to as L network coded (NC) messages, and forwards them to the destination. The destination then attempts to recover all K users' messages by combining its received signals and the NC messages obtained from the relay. We develop an explicit expression on the selection of the coefficients of the NC messages at the relay that minimizes the end-to-end error probability at a high signal to noise ratio regime. Numerical results demonstrate that our proposed scheme outperforms the benchmark scheme significantly in an MARN.
A physical-layer network coding (PNC) aided two-way relay scheme is proposed for Transmitted-Reference (TR) UWB networks. In particular, a novel noncoherent UWB-PNC detector is investigated for the TR-UWB networks. In...
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ISBN:
(纸本)9781424492688
A physical-layer network coding (PNC) aided two-way relay scheme is proposed for Transmitted-Reference (TR) UWB networks. In particular, a novel noncoherent UWB-PNC detector is investigated for the TR-UWB networks. Inheriting the simplicity of the TR-UWB receiver, the proposed PNC detector is based on the autocorrelation receiver (AcR) with simple structure, which effectively suppresses the multi-user interference and harvests the multipath energy. Equipped with the proposed TR UWB-PNC detector, the relay node first detects the bitwise XORed symbol directly from the overlapped information bearing waveforms transmitted from the source nodes, then broadcasts the estimate of the XORed symbol to achieve efficient two-way relay. Simulation results show that, compared with the non-relay, one-way relay and two-way relay with time division multiple access (TDMA) and network coded broadcasting (NCBC), the proposed PNC aided two-way scheme significantly improves both the energy and spectral efficiencies of the TR-UWB networks.
physical-layer network coding (PNC) can potentially boost the throughput of a two-way relay network by 100% compared with conventional packet forwarding schemes. However, the complexity of PNC channel decoders can be ...
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ISBN:
(纸本)9781479966646
physical-layer network coding (PNC) can potentially boost the throughput of a two-way relay network by 100% compared with conventional packet forwarding schemes. However, the complexity of PNC channel decoders can be considerably higher than the complexity of channel decoders for point-to-point communication systems. Although many PNC channel decoders proposed to date have good decoding performance, they may not be feasibly implemented in practical systems due to their high computation complexities. This paper presents a reduced-complexity decoder (RCD), a PNC decoder with adjustable decoding complexity that is amenable to real-time implementation. We experimentally evaluate the performance-complexity trade-off of RCD. Our experimental results show that RCD can achieve substantial throughput gain over state-of-the-art decoders proposed for real-time PNC systems.
networkcoding recognized as an efficient solution on improving network throughput is a hot spot in the area of wireless network. However, interference affects quality of communication seriously, which is a harmful fa...
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ISBN:
(纸本)9783642232251
networkcoding recognized as an efficient solution on improving network throughput is a hot spot in the area of wireless network. However, interference affects quality of communication seriously, which is a harmful factor in wireless fading environment. One protocol named physical-layer network coding not only increase network throughput but also takes advantage of interference between signals. How to separate the mixed signal resulting from the broadcast nature of wireless channel is an area with little discussion. This paper firstly proposes a PNC decoding solution for mixed signal separation in Multi Access Relay Channel(MARC) model. Then we use our estimation result about the channel coefficients to give a discussion on the capacity theorem of MARC model using PNC. In conclusion, the simulation result tells that the proposed method ARD PNC performs well in PNC with higher bandwidth utility and lower error rate. At the same time, the capacity using PNC is also improved comparing to traditional direct transmission.
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