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adaptive Error-Correction coding Scheme for Underwater Acoustic Communication Networks

IEEE JOURNAL OF OCEANIC ENGINEERING 2015年第1期40卷 104-114页

作者： Diamant, Roee Lampe, Lutz Univ British Columbia Dept Elect & Comp Engn Vancouver BC V6T 1Z4 Canada

Underwater acoustic communication networks (UWANs) have recently attracted much attention in the research community. Two properties that set UWANs apart from most radio-frequency wireless communication networks are the long propagation delay and the possible sparsity of the network topology. This in turn offers opportunities to optimize throughput through time and spatial reuse. In this paper, we propose a new adaptive coding method to realize the former. We consider time-slotted scheduling protocols, which are a popular solution for contention-free and interference-free access in small-scale UWANs, and exploit the surplus guard time that occurs for individual links for improving transmission reliability. In particular, using link distances as side information, transmitters utilize the available portion of the time slot to adapt their code rate and increase reliability. Since increased reliability trades off with energy consumption per transmission, we optimize the code rate for best tradeoff, considering both single and multiple packet transmission using the incremental redundancy hybrid automatic repeat request (IR-HARQ) protocol. For practical implementation of this adaptive coding scheme, we consider punctured and rateless codes. Simulation results demonstrate the gains achieved by our coding scheme over fixed-rate error-correction codes in terms of both throughput and consumption of transmitted energy per successfully delivered packet. We also report results from a sea trial conducted at the Haifa harbor, which corroborate the simulations.

关键词： adaptive coding incremental redundancy automatic repeat request (IR-HARQ) rateless codes underwater acoustic communication

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Alternative Algorithms Involving Alphabetical coding and Limited Length Encoding in Lossless Data Compression of Text Files

Alternative Algorithms Involving Alphabetical Coding and Lim...

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International Symposium on Fundamentals of Electrical Engineering (ISFEE)

作者： Radescu, Radu Univ Politehn Bucuresti Fac Elect Telecommun & Informat Technol Appl Elect & Informat Engn Dept 1-3 Iuliu Maniu Blvd RO-061071 Bucharest Romania

ISBN: (纸本)9781467395755

coding algorithms are generally aimed at minimizing the output code length encoding speed once the code has been designed. Moreover, most codes use a binary alphabet. This paper examines other issues related to coding, such as additional constraints imposed on the channel. Code generation will be considered where there is a limit on code words. Limits the application of such systems is a practical example of data compression where fast decoding is essential. When all code words correspond to a single word in memory (usually 32 bits, but there are situations that take 64-bit) can be used canonical decoding. If the deadline cannot be guaranteed, however, required the use of slower decoding methods. This paper also deals with the alphabetic code generation, where lexicographic arrangement of words by their code symbols must correspond to the original order in which the symbols were taken coding system. When an alphabetic code is used to compress a database that can be sorted in the same, order they would have had if the database records were first decompressed and then sorted. It also corresponds to alphabetic code trees binary search trees, which have applications in a wide variety of search problems. Assumption that the symbols are sorted by probability is not suitable for this scenario. The problem of finding codes for non-binary alphabets channel will be examined in detail. The subsequent experimental results cover the problem of alphabetic coding and of limited length coding.

关键词： Data compression Source coding Compression algorithms adaptive coding Text processing

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FPGA Implementation of Advanced FEC Schemes for Intelligent Aggregation Networks 8

FPGA Implementation of Advanced FEC Schemes for Intelligent ...

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Conference on Optical Metro Networks and Short-Haul Systems VIII

作者： Zou, Ding Djordjevic, Ivan B. Univ Arizona Dept Elect & Comp Engn 1230 E Speedway Blvd Tucson AZ 85719 USA

ISBN: (纸本)9781510600089

In state-of-the-art fiber-optics communication systems the fixed forward error correction (FEC) and constellation size are employed. While it is important to closely approach the Shannon limit by using turbo product codes (TPC) and low-density parity-check (LDPC) codes with soft-decision decoding (SDD) algorithm;rate-adaptive techniques, which enable increased information rates over short links and reliable transmission over long links, are likely to become more important with ever-increasing network traffic demands. In this invited paper, we describe a rate adaptive non-binary LDPC coding technique, and demonstrate its flexibility and good performance exhibiting no error floor at BER down to 10(-15) in entire code rate range, by FPGA-based emulation, making it a viable solution in the next-generation high-speed intelligent aggregation networks.

关键词： Fiber-optics communications low-density parity-check (LDPC) codes adaptive coding FPGA implementation intelligent aggregation networks

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Cognitive HF Communication System with adaptive Complementary Codes 8

Cognitive HF Communication System with Adaptive Complementar...

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8th International Conference on Ubiquitous and Future Networks (ICUFN)

作者： Vartiainen, Johanna Pirinen, Pekka Vuohtoniemi, Risto Univ Oulu Ctr Wireless Commun Oulu Finland

ISBN: (纸本)9781467399913

High frequency (HF) band covers frequencies between 3-30 MHz. With wavelengths of 10-100 m, HF band enables communications over a very long distances though a skywave propagation. As HF band has several benefits like versatility and large coverage area, it suffers phenomena like rapidly changing environment and strong interference. The cognitive radio concept which adapts to the changes in the environment offers tools to solve those problems. In this paper, HF band challenges caused by ionospheric break and interference are solved using databases and complementary codes that adapt to the characteristics of different data transmission requirements. The goal is to optimize used frequencies based on the data transmission needs.

关键词： cognitive HF communication system adaptive coding complementary coding

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adaptive coding based on a new slice type in surveillance systems

Adaptive coding based on a new slice type in surveillance sy...

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International Colloquium on Signal Processing & Its Applications, CSPA

作者： Li Muchen Xin Jin Satoshi Goto Graduate School of Information Production and System Waseda University 2-7 Hibikino Kitakyushu 808-0135 Japan Graduate School of Information Production and System Waseda University Kitakyushu Japan

In surveillance systems, low bit rate video coding is necessary to reduce the storage and bandwidth consumption, especially for high definition video coding. In [1], we proposed an adaptive coding method to code the active regions with traditional slices and background with the proposed S slice respectively. The S slice contains less syntax elements than the conventional P slice. This paper further analyzes the influence factors to the S slice coding. Moreover, a control module is proposed to enable the S slice coding and to find the best partition pattern between active regions and background that could get the most bit reduction [3], [4].

关键词： adaptive coding Encoding Noise level Noise Bit rate Syntactics Testing

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Context-dependent coding and gain control in the auditory system of crickets

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EUROPEAN JOURNAL OF NEUROSCIENCE 2015年第7期42卷 2390-2406页

作者： Clemens, Jan Rau, Florian Hennig, R. Matthias Hildebrandt, K. Jannis Humboldt Univ Dept Biol Behav Physiol Grp Berlin Germany Bernstein Ctr Computat Neurosci Berlin Berlin Germany Princeton Univ Princeton Neurosci Inst Princeton NJ 08540 USA Carl von Ossietzky Univ Oldenburg Cluster Excellence Hearing4all Dept Neurosci D-26111 Oldenburg Germany Carl von Ossietzky Univ Oldenburg Res Ctr Neurosensory Sci D-26111 Oldenburg Germany

Sensory systems process stimuli that greatly vary in intensity and complexity. To maintain efficient information transmission, neural systems need to adjust their properties to these different sensory contexts, yielding adaptive or stimulus-dependent codes. Here, we demonstrated adaptive spectrotemporal tuning in a small neural network, i.e. the peripheral auditory system of the cricket. We found that tuning of cricket auditory neurons was sharper for complex multi-band than for simple single-band stimuli. Information theoretical considerations revealed that this sharpening improved information transmission by separating the neural representations of individual stimulus components. A network model inspired by the structure of the cricket auditory system suggested two putative mechanisms underlying this adaptive tuning: a saturating peripheral nonlinearity could change the spectral tuning, whereas broad feed-forward inhibition was able to reproduce the observed adaptive sharpening of temporal tuning. Our study revealed a surprisingly dynamic code usually found in more complex nervous systems and suggested that stimulus-dependent codes could be implemented using common neural computations.

关键词： adaptive coding auditory coding cricket gain control inhibition

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REAL-TIME RATE-ADAPTABLE coding FOR FADING CHANNELS

REAL-TIME RATE-ADAPTABLE CODING FOR FADING CHANNELS

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IEEE Signal Processing and Signal Processing Education Workshop (SP/SPE)

作者： Schmidt, Sam Harrison, Willie K. Univ Colorado Colorado Springs Dept Elect & Comp Engn Colorado Springs CO 80918 USA

ISBN: (纸本)9781467391696

In this paper, a new adaptive-rate convolutional coding system for maximizing the throughput over slowly fading channels is presented. The scheme is capable of adapting on the fly to fading conditions without the delay inherent in ARQ-based adaptive-rate strategies. The system employs a bank of encoders, and the current encoder is selected as a function of the channel state information obtained through a periodically transmitted feedback training sequence. This scheme does not require rate compatibility in the code bank, and can therefore make use of the best-known codes of any rates with arbitrary constraint lengths. At the receiver, an innovative decoding method based on the well-known Viterbi algorithm is employed. Knowledge of the encoder choices is not required at the decoder due to its ability to seamlessly track encoder transitions through an expanded Viterbi trellis. The system provides a hassle-free solution to achieving high-rate communications over fading channels.

关键词： Viterbi algorithm adaptive coding fading forward error correction

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Comments and Corrections to "An Efficient adaptive Binary Arithmetic Coder Based on Logarithmic Domain" [Nov 15 4225-4239]

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IEEE transactions on image processing : a publication of the IEEE Signal Processing Society 2017年第10期26卷 5031页

作者： Euee Seon Jang Jong-Wha Chong Department of Computer Science Hanyang University Seoul South Korea Department of Electronics Engineering Hanyang University Seoul South Korea

This correspondence is to address the corrections to the published paper titled "An efficient adaptive binary arithmetic coder based on logarithmic domain".

关键词： Video coding adaptive coding Binary codes Probability Data compression

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Context based compression of FASTQ data

Context based compression of FASTQ data

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International Symposium on Circuits and Systems

作者： Rama Srikanth Mallavarapu Pandu Kumar Chinnamalliah Ajit S. Bopardikar TaeJin Ahn SAIT-India Labs Samsung R&D Institute India-Bangalore (SRI-B) India SAIT-India Labs Samsung Advanced Institute of Technology Korea

ISBN: (纸本)9781479953424

With advances in Next Generation Sequencing (NGS) technologies, the amount of genomic data produced is growing exponentially. Efficient compression is therefore vital for archiving, retrieval and transfer of raw sequencing data. NGS data consisting of sequence information along with the associated quality scores and sequence identifiers is stored in the FASTQ format. In this paper, we present lossless methdologies to compress components of a FASTQ file. The proposed system explores p rediction by partial matching methods (PPM) for building higher order context models to compress FASTQ data using adaptive arithmetic coding (AAC). We analyze crucial parameters in AAC to further improve overall compression of our system. We compare the performance of the proposed system with existing benchmarks for a sample data set of 6 standard FASTQ files. The proposed method provides gains of up to 15% compared to the best existing benchmark. We also show that the proposed methodology provides gains on overall storage space across the sample data set.

关键词： Data sampling storage spaces automatic amplitude control compression Lossless COMPRESSED adaptive coding BENCHMARKS Context modeling Dataset Gain

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How distinct is the coding of face identity and expression? Evidence for some common dimensions in face space

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COGNITION 2015年 142卷 123-137页

作者： Rhodes, Gillian Pond, Stephen Burton, Nichola Kloth, Nadine Jeffery, Linda Bell, Jason Ewing, Louise Calder, Andrew J. Palermo, Romina Univ Western Australia Sch Psychol ARC Ctr Excellence Cognit & Its Disorders Crawley WA 6009 Australia Univ London Birkbeck Dept Psychol Sci London England MRC Cognit & Brain Sci Unit Cambridge England

Traditional models of face perception emphasize distinct routes for processing face identity and expression. These models have been highly influential in guiding neural and behavioural research on the mechanisms of face perception. However, it is becoming clear that specialised brain areas for coding identity and expression may respond to both attributes and that identity and expression perception can interact. Here we use perceptual aftereffects to demonstrate the existence of dimensions in perceptual face space that code both identity and expression, further challenging the traditional view. Specifically, we find a significant positive association between face identity aftereffects and expression aftereffects, which dissociates from other face (gaze) and non-face (tilt) aftereffects. Importantly, individual variation in the adaptive calibration of these common dimensions significantly predicts ability to recognize both identity and expression. These results highlight the role of common dimensions in our ability to recognize identity and expression, and show why the high-level visual processing of these attributes is not entirely distinct. (C) 2015 Elsevier B.V. All rights reserved.

关键词： Face perception Face aftereffects adaptive coding Face recognition

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