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distributed Quasi-Orthogonal Space-Time Block Code for Four Transmit Antennas with Information Exchange Error Mitigation

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KSII TRANSACTIONS ON INTERNET AND INFORMATION SYSTEMS 2013年第10期7卷 2411-2429页

作者： Tseng, Shu-Ming Wang, Shih-Han Natl Taipei Univ Technol Dept Elect Engn Taipei 106 Taiwan

In this paper, we extend the case of information exchange error mitigation for the distributed orthogonal space-time block code (DOSTBC) for two transmit antennas to distributed quasi-orthogonal space-time block code (DQOSTBC) for four transmit antennas. A rate 1 full-diversity DQOSTBC for four transmit antennas is designed. The code matrix changes according to different information exchange error cases, so full diversity is maintained even if not all information exchange is correct. We also perform analysis of the pairwise error probability. The performance analysis indicates that the proposed rate 1 DQOSTBC outperforms rate 1/2 DOSTBC for four transmit antennas at the same transmission rate, which is confirmed by the simulation results.

关键词： Cooperative communications distributed coding performance analysis diversity product cyclic redundancy check

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Steepest-Descent Optimization of CDMA Signatures for Multiple Correlated Sources With Applications to Joint Source-Channel coding

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IEEE TRANSACTIONS ON COMMUNICATIONS 2015年第4期63卷 1343-1354页

作者： Yahampath, Pradeepa Univ Manitoba Dept Elect & Comp Engn Winnipeg MB R3T V6 Canada

An approach to transmitting multiple correlated sources over a Gaussian multiple-access channel (GMAC) using code-division multiple-access (CDMA) is investigated. A block coordinate descent (BCD) algorithm is presented which can be used to optimize CDMA signatures for a given source covariance matrix under individual transmitter power constraints. This algorithm can be used to design non-orthogonal CDMA signatures for GMACs with arbitrary input alphabets, fading, and colored noise. While the main focus has been the design of signatures which minimize the mean square error (MSE) of linear decoding, the algorithm can also be used to design signatures which maximize the input-output mutual information of the channel. This paper investigates the uncoded transmission of Gaussian sources and the coded transmission of binary sources over a GMAC using joint source-channel (JSC) optimized CDMA signatures under constraints on transmitter power and channel bandwidth, scenarios relevant to wireless sensor networks. By using simple coding schemes which only rely on linear multi-user detection and independent channel decoding of a large number of sources, it is demonstrated that CDMA-based JSC coding can exploit inter-source correlation to achieve lower distortion (Gaussian sources) or higher rates (binary sources) compared to conventional separate source-channel (SSC) coding over the same channel bandwidth.

关键词： Gaussian multiple-access channels code-division multiple access steepest-descent optimization block-coordinate descent algorithms distributed coding

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The design and performance of distributed LT codes

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IEEE TRANSACTIONS ON INFORMATION THEORY 2007年第10期53卷 3740-3754页

作者： Puducheri, Srinath Kliewer, Joerg Fuja, Thomas E. Univ Notre Dame Dept Elect Engn Notre Dame IN 46556 USA

This paper describes techniques to decompose LT codes (a class of rateless erasure-correcting codes) into distributed LT (DLT) codes. DLT codes can be used to independently encode data from multiple sources in a network in such a way that, when the DLT-encoded packets are combined at a common relay, the resulting bit stream (called a modified LT (MLT) code) has a degree distribution approximating that of an LT code, with simulations indicating comparable performance. In essence, DLT codes are designed so that the final stage of encoding for erasure correction can be carried out by a low-complexity relay that selectively xoRs the bit streams generated at each source and transmits the result to the sink. This paper presents results for two-source and four-source networks. It is shown that, when the relay-to-sink link is the bottleneck, the DLT/MLT approach can yield substantial performance benefits compared with a competing strategy wherein each of the sources uses its own independent LT encoder and the resulting bit streams are time-multiplexed through the relay.

关键词： distributed coding erasure correction LT codes relay networks

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distributed Decoding for Coded distributed Computing

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IEEE INTERNET OF THINGS JOURNAL 2021年第14期9卷 12555-12562页

作者： Yazdanialahabadi, Arash Ardakani, Masoud Univ Alberta Elect & Comp Engn Dept Edmonton AB T6G 2R3 Canada

In distributed computing, when a large number of helper nodes assist a master node to finish a large task, the main challenge is when some of these helpers straggle. Several coded distributed computing schemes exist that resolve the straggling problem. In these solutions, however, the decoding remains a responsibility of the master node. The complexity of decoding can be significant and increase the execution time considerably. In this work, we propose a multilayer coding strategy that allows some helpers to assist with the decoding. With this multilayer structure, the original decoding is performed by some decoding helpers, and the master only minimally participates in decoding to make every layer reliable. The optimization problem to minimize the overall completion time is also studied and shown to have a simple solution in almost all practical scenarios.

关键词： Decoding Task analysis Codes Encoding distributed computing Internet of Things Complexity theory distributed coding distributed computing edge computing heterogeneous network matrix multiplication

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Self-organizing information fusion and hierarchical knowledge discovery: a new framework using ARTMAP neural networks

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NEURAL NETWORKS 2005年第3期18卷 287-295页

作者： Carpenter, GA Martens, S Ogas, OJ Boston Univ Ctr Adapt Syst Dept Cognit & Neural Syst Boston MA 02215 USA

Classifying novel terrain or objects from sparse, complex data may require the resolution of conflicting information from sensors working at different times, locations, and scales, and from sources with different goals and situations. Information fusion methods can help resolve inconsistencies, as when evidence variously suggests that an object's class is car, truck, or airplane. The methods described here address a complementary problem, supposing that information from sensors and expert, is reliable though inconsistent, as when evidence suggests that an object's class is car. vehicle, and man-made. Underlying relationships among classes are assumed to be unknown to the automated system or the human user. The ARTMAP information fusion system uses distributed code representations that exploit the neural network's capacity for one-to-many learning in order to produce self-organizing expert systems that discover hierarchical knowledge structures. The fusion system infers multi-level relationships among groups of output classes, without any supervised labeling of these relationships. The procedure is illustrated with two image examples, but is not limited to the image domain. (c) 2005 Elsevier Ltd. All rights reserved.

关键词： ARTMAP adaptive resonance theory (ART) information fusion pattern recognition data mining remote sensing distributed coding association rules multi-sensor fusion

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distributed ARTMAP: a neural network for fast distributed supervised learning

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NEURAL NETWORKS 1998年第5期11卷 793-813页

作者： Carpenter, GA Milenova, BL Noeske, BW Boston Univ Dept Cognit & Neural Syst Boston MA 02215 USA Boston Univ Ctr Adapt Syst Boston MA 02215 USA

distributed coding at the hidden layer of a multi-layer perceptron (MLP) endows the network with memory compression and noise tolerance capabilities. However, an MLP typically requires slow off-line learning to avoid catastrophic forgetting in an open input environment. An adaptive resonance theory (ART) model is designed to guarantee stable memories even with fast on-line learning. However, ART stability typically requires winner-take-all coding, which may cause category proliferation in a noisy input environment. distributed ARTMAP (dARTMAP) seeks to combine the computational advantages of MLP and ART systems in a real-time neural network for supervised learning. An implementation algorithm here describes one class of dARTMAP networks. This system incorporates elements of the unsupervised dART model, as well as new features, including a content-addressable memory (CAM) rule for improved contrast control at the coding field. A dARTMAP system reduces to fuzzy ARTMAP when coding is winner-take-all. Simulations show that dARTMAP retains fuzzy ARTMAP accuracy while significantly improving memory compression. (C) 1998 Elsevier Science Ltd. All rights reserved.

关键词： distributed ARTMAP adaptive resonance ART ARTMAP distributed coding fast learning supervised learning neural network

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New Soft-Encoding Relay (SoER) Mechanisms for Wireless Relay Systems: Convolutional and Turbo Constructions

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IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 2016年第4期15卷 2443-2457页

作者： Lu, Xuanxuan Li, Jing Liu, Yang Lehigh Univ Dept Elect & Comp Engn Bethlehem PA 18015 USA

A two-hop parallel-relay network is considered in this paper. Conventional schemes investigating the coding strategies at the relay(s) have largely focused on hard encoding, with the exception of one pioneering strategy that proposed a soft distributed encoding using the soft estimate (tanh-based) information. To fully harness the gain promised by soft encoding, this paper focuses on distributed soft encoding strategies at the relays. Unlike the previous work that favors the tanh form for soft encoding, we advocate the range-limited log-likelihood ratios (rLLR) as a better way for the relays to capture the reliability of the messages sent by the sender, and especially to further soft-encode these messages. Based on this, we develop a simple but effective soft-encoding relay (SoER) strategy that exploits the useful features of rLLR. Specifically, the close resemblance of rLLR to the tanh form allows us to derive a very simple convolutional encoding, and the piece-wise linearity of rLLR allows us to evaluate the codeword probability density function (PDF) analytically, which further allows us to derive a Viterbi decoding algorithm using a more precise PDF (in addition to the Gaussian-approximated Viterbi algorithm). We finally extend the nonrecursive convolutional SoER strategy to the turbo SoER strategy. Simulation results confirm the efficiency of the new proposed SoER schemes.

关键词： Cooperative communications distributed coding soft information maximum likelihood estimation

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Optimized Relay Selection Strategy Based on GF(2^p) for Adaptive Network Coded Cooperation

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IEICE TRANSACTIONS ON COMMUNICATIONS 2011年第10期E94B卷 2912-2915页

作者： Zhang, Kaibin Yin, Liuguo Lu, Jianhua Tsinghua Univ Dept Elect Engn Beijing 100084 Peoples R China Tsinghua Univ Sch Aerosp Beijing 100084 Peoples R China

Adaptive network coded cooperation (ANCC) scheme may have excellent performance for data transmission from a large collection of terminals to a common destination in wireless networks. However, the random relay selection strategy for ANCC protocol may generate the distributed low-density parity-check (LDPC) codes with many short cycles which may cause error floor and performance degradation. In this paper, an optimized relay selection strategy for ANCC is proposed. Before data communication, by exploiting low-cost information interaction between the destination and terminals, the proposed method generates good assembles of distributed LDPC codes and its storage requirement reduces dramatically. Simulation results demonstrate that the proposed relay selection protocol significantly outperforms the random relay selection strategy.

关键词： cooperative wireless network adaptive network coded cooperation (ANCC) low-density parity-check (LDPC) codes distributed coding

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Self-Concatenated Code Design and its Application in Power-Efficient Cooperative Communications

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IEEE COMMUNICATIONS SURVEYS AND TUTORIALS 2012年第3期14卷 858-883页

作者： Butt, Muhammad Fasih Uddin Ng, Soon Xin Hanzo, Lajos CIIT Ctr Hlth Res Dept Elect Engn Islamabad 44000 Pakistan Univ Southampton Sch Elect & Comp Sci Chair Telecommun Southampton SO17 1BJ Hants England

In this tutorial, we have focused on the design of binary self-concatenated coding schemes with the help of EXtrinsic Information Transfer (EXIT) charts and Union bound analysis. The design methodology of future iteratively decoded self-concatenated aided cooperative communication schemes is presented. In doing so, we will identify the most important milestones in the area of channel coding, concatenated coding schemes and cooperative communication systems till date and suggest future research directions.

关键词： Near-Capacity Code Design Self-Concatenated Convolutional Codes SECCC EXIT charts Iterative Decoding Cooperation Diversity distributed coding

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distributed learning, recognition, and prediction by ART and ARTMAP neural networks

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NEURAL NETWORKS 1997年第8期10卷 1473-1494页

作者： Carpenter, GA Boston University BostonMAU.S.A.

A class of adaptive resonance theory (ART) models for learning, recognition, and prediction with arbitrarily distributed code representations is introduced. distributed ART neural networks combine the stable fast learning capabilities of winner-take-all ART systems with the noise tolerance and code compression capabilities of multilayer perceptrons. With a winner-take-all code, the unsupervised model dART reduces to fuzzy ART and the supervised model dARTMAP reduces to fuzzy ARTMAP. With a distributed code, these networks automatically apportion learned changes according to the degree of activation of each coding node, which permits fast as well as slow learning without catastrophic forgetting. distributed ART models replace the traditional neural network path weight with a dynamic weight equal to the rectified difference between coding node activation and an adaptive threshold Thresholds increase monotonically during learning according to a principle of atrophy due to disuse. However, monotonic change at the synaptic level manifests itself as bidirectional change at the dynamic level, where the result of adaptation resembles long-term potentiation (LTP) for single-pulse or low frequency test inputs but can resemble long-term depression (LTD) for higher frequency test inputs. This paradoxical behavior is traced to dual computational properties of phasic and tonic coding signal components. A parallel distributed match-reset-search process also helps stabilize memory. Without the match-reset-search system, dART becomes a type of distributed competitive learning network. (C) 1997 Elsevier Science Ltd.

关键词： distributed ART adaptive resonance theory distributed coding dynamic weight fast learning competitive learning ARTMAP neural network

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