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distributed channel coding for Underwater Acoustic Cooperative Networks

IEEE TRANSACTIONS ON COMMUNICATIONS 2014年第3期62卷 848-856页

作者： Jalil, Amir Minayi Ghrayeb, Ali Concordia Univ Dept Elect & Comp Engn Montreal PQ H3G 1M8 Canada Texas A&M Univ Qatar Dept Elect & Comp Engn Qatar Qatar

Multiuser cooperative schemes usually rely on relay selection or channel selection to avoid deep fading and achieve diversity while maintaining acceptable spectral efficiency. In some applications such as underwater acoustic communications, the low speed of the acoustic wave results in a very long delay between the channel state information (CSI) measurement time and the relay assignment time, which leads to a severely outdated CSI. To remedy this, we propose distributed coding schemes that aim at achieving good diversity-multiplexing trade-off (DMT) for multiuser scenarios where CSI is not available for resource allocation. We consider a network with multiple source nodes, multiple relay nodes, and a single destination. We first introduce a distributed linear block coding scheme, including Reed-Solomon codes, where each relay implements a column of the generator matrix of the code, and soft decision decoding is employed to retrieve the information at the destination side. We derive the end-to-end error performance of this scheme and show that the achievable diversity equals the minimum Hamming distance of the underlying code, while its DMT outperforms that of existing schemes. We extend the proposed scheme to distributed convolutional codes, and show that achieving higher diversity orders is also possible.

关键词： Cooperative networks distributed channel coding underwater acoustic channels

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Improved Diversity-Multiplexing Tradeoff for Underwater Acoustic channels Based on distributed channel coding

Improved Diversity-Multiplexing Tradeoff for Underwater Acou...

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IEEE International Symposium on Personal, Indoor and Mobile Radio Communications

作者： Amir Minayi Jalil Ali Ghrayeb ECE Dept. Concordia University Montreal Canada

ISBN: (纸本)9781467362337

Multiuser cooperative schemes usually rely on relay selection or channel selection to avoid deep fading and achieve diversity for all source nodes while maintaining acceptable spectral efficiency. This requires estimating the channel state information (CSI) and reporting it back to the resource allocator. Then the resource allocator needs to inform each node about its task. In some applications, it is impractical to collect the required CSI. For example, in underwater acoustic channels, the low speed of the acoustic wave (500 m/s) leads to a very long delay between the measured CSI and the reported CSI, making the provided CSI severely "outdated". To remedy this, we propose a new distributed coding scheme to avoid deeply faded channels and achieve cooperative diversity for multiuser applications where CSI is not available. We consider a network consisting of multiple sources, multiple relays, and a single destination. The proposed scheme is based on a distributed implementation of linear block codes and achieves a better diversity-multiplexing tradeoff (DMT) compared to the competitive schemes. In this scheme, each relay node implements a column of the generator matrix of the code. Each relay receives the symbols from one or more source nodes and performs modulo-q addition on the decoded symbols and retransmits the result to the destination. Finally, soft decoding is employed at the destination to retrieve the transmitted information. We prove that the proposed scheme achieves diversity d_mi_n for the end-to-end (E2E) performance, where d_mi_n is the minimum distance of the underlying code.

关键词： distributed channel coding CSI underlying code

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distributed Low-Density Lattice Codes

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IEEE COMMUNICATIONS LETTERS 2016年第1期20卷 77-80页

作者： Chen, Bin Jayakody, Dushantha N. K. Flanagan, Mark F. Univ Coll Dublin Sch Elect Elect & Commun Engn Dublin 4 Ireland Univ Tartu Inst Comp Sci EE-51409 Tartu Estonia

This letter presents a novel distributed LDLC (D-LDLC) relaying scheme for the classical relay channel. The relay node decodes LDLC packets from the source and forwards an additional parity message to the destination. The destination then performs joint decoding in order to exploit the available coding gain as well as diversity gain. First, assuming AWGN links, density evolution is used to optimize the noise threshold of the overall parity-check matrix, and this method is shown to produce good finite-length D-LDLC designs. Then, we provide results for the optimized D-LDLCs under Rayleigh fading channel conditions. Joint decoding based on D-LDLC is shown to provide approximately 3 dB gain over distributed 4-PAM turbo codes under the same conditions (data rate and overall transmission power).

关键词： Low-density lattice codes (LDLCs) distributed channel coding coded cooperation relay channel

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Link adaptation algorithm for distributed coded transmissions in cooperative OFDMA systems

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TELECOMMUNICATION SYSTEMS 2015年第4期59卷 477-489页

作者： Varga, Mihaly Badiu, Mihai-Alin Bota, Vasile Tech Univ Cluj Napoca Dept Commun Cluj Napoca 40027 Romania Aalborg Univ Dept Elect Syst DK-9220 Aalborg Denmark

This paper proposes a link adaptation algorithm for cooperative transmissions in the down-link connection of an OFDMA-based wireless system. The algorithm aims at maximizing the spectral efficiency of a relay-aided communication link, while satisfying the block error rate constraints at both the relay and the destination nodes. The optimal solution would be to perform an exhaustive search over a high-dimensional space determined by all possible combinations of modulations, code rates and information block lengths on the individual channels of the cooperative link;clearly, such an approach has an intractable complexity. Our solution is to use a link performance prediction method and a trellis diagram representation such that the resulting algorithm outputs the link configuration that conveys as many information bits as possible and also fulfilling the block error rate constraints. The proposed link adaptation algorithm has linear complexity with the number of available resource blocks, while still provides a very good performance, as shown by simulation results.

关键词： Cooperative wireless communications distributed channel coding Link adaptation Link performance prediction

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Trellis coded modulation based distributed channel coding

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IET COMMUNICATIONS 2009年第7期3卷 1071-1080页

作者： Nagaraj, S. V. Bell, M. R. San Diego State Univ Dept Elect & Comp Engn San Diego CA 92182 USA Purdue Univ Sch Elect & Comp Engn W Lafayette IN 47907 USA

A novel technique is described for distributed channel coding in wireless communication networks. The protocol is based on a block fading model of the multi-user uplink channel and on adapting multidimensional trellis coded modulation techniques to a coding theorem derived for the block fading channel. The coded modulation (CM) protocol is designed to optimise code performance, especially at high spectral efficiencies. The CM protocol is very simple to implement at the cooperating users. Complexity is completely transferred to the destination. The latency of the protocol is only one symbol. The CM protocol achieves full diversity order equal to the number of cooperating users and maximises coding gains by designing the code for the specific modulation used. We derive analytical results and present simulation results showing the benefits of CM protocol over other comparable schemes.

关键词： channel coding fading channels multiuser channels Protocols coded modulation protocol design Radio links and equipment multiuser uplink channel wireless communication networks diversity reception multidimensional trellis coded modulation radio networks trellis coded modulation distributed channel coding protocols spectral efficiency block fading model Codes

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Link Adaptation Algorithm for distributed Coded Transmissions in Relay-Aided OFDMA Systems

Link Adaptation Algorithm for Distributed Coded Transmission...

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35th International Conference on Telecommunications and Signal Processing (TSP)

作者： Varga, Mihaly Badiu, Mihai-Alin Bota, Vasile Tech Univ Cluj Napoca Dept Commun Cluj Napoca 40027 Romania

ISBN: (纸本)9781467311182

We propose a link adaptation algorithm for cooperative transmissions in an OFDMA-based wireless system. The algorithm aims at maximizing the spectral efficiency of a relay-aided communication link, while satisfying the block error rate constraints at both the relay and the destination nodes. The optimal solution would be to perform an exhaustive search over a high-dimensional space determined by all possible combinations of modulations, code rates and information block lengths on the individual links;clearly, such an approach has an intractable complexity. Our solution is to use a link performance prediction method and a trellis diagram representation such that the resulting algorithm outputs a link configuration that conveys as many as possible information bits and also fulfills the block error rate constraints. The proposed link adaptation algorithm has linear complexity with the number of available resource blocks, but still provides a very good performance, as shown by simulation results.

关键词： cooperative wireless communications distributed channel coding link adaptation link performance prediction

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