Johan Lassing, Anders Persson, Tony Ottosson et al. · 2007
The performa,- in terms of bit-error proba, ity of low-ra convolutiona codes isa ddressed. The Heller bound on the free dista is revisedai a na,- e formula is given. A discussion of the keypa,- determining the code performa ar how toobta good codes is followed bya compa of codes of va ra fora fixedconstra t length. It is concluded tha simply lowering the ra does not givea grea performa gaforma the encoder complexity must be increa, toincrea the coding gag, This observa tion is used to propose modifica,- toa previously suggested code-sprea CDMA system. Keyte ds--- low-ra convolutiona codes,code-sprea CDMA,Heller bound,dista spectrum,code performaor - I. Introducti The class of con volutionj error correctin codes have been used exten7P ely over the years to provide reliable communm0++#= over chanPH6 havin a low signHB0jBfl=BP0 ratio. Amon the advan tages of con volutionj codes over, e.g., block codes is the availability of a maximum-likelihood deco din algorithm for the en tire class of con volutionj codes able to exploit soft in0=7#Bfl0j in the deco din0 Amon the disadvan tages can bemen tionfl that to realize a con volutionB code comparablein performanj to a block code of large block lenH# (> 100) a prohibitively complex ML decoder is required. Amon therecen t application of con volutionj codesin wireless commun=6P=#0 can be men tionfi the in terestin idea ofusin low-rate (that is, few bitsin man y bits out) con volutionH codes for codin in=flfl#+0j mobile users an then simultan0jH=+ tranjH=+#=0 several users to the common base station usin the same chan6B6 This scheme, kn wn as code-spread code-di- multi access or CSCDMA, has been conH0j=#= in e.g., [1] [2] [3]. In this paper we address issuesrelatin to the performanr of low-ratecon volutionj codesin genH6flfl an...
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Umar Farooq, Muhammad · Lund University Publications (Lund University) · 2022
Modern coding theory is based on the foundation of the sparse codes on graphs, such as the low-density parity-check (LDPC) codes, and the turbo-like codes (TCs) with component convolutional codes. The success of the LDPC codes and the TCs lies in their ability to perform low-complexity iterative message passing decoding procedures. The iterative message passing decoders that exchange messages probabilities, or beliefs, within the code graph are known as the belief propagation (BP) decoders. The BP decoders are sub-optimal, whereas maximum-a-posteriori (MAP) decoders for these codes are computationally infeasible. These codes can be optimized for their BP decoding performance, which improves their error rate performance in the waterfall region at the cost of a performance loss in the error-floor region. On the contrary, optimizing these codes for the MAP performance results in an improved performance in the error-floor region at the expense of a degraded performance in the waterfall region.In practice, the BP decoding performance of the LDPC codes and the TCs, in the asymptotic block length regime, is determined by computing their BP decoding thresholds from the density evolution (DE), or the extrinsic information transfer (EXIT) chart techniques. The MAP decoding thresholds can be obtained with an application of the area theorem to the BP decoder performance. The graphs of the LDPC codes and the TCs are optimized for the BP, and the MAP decoding performance by using their decoding thresholds. For very large block lengths, spatially coupled (SC) versions of LDPC codes, and the TCs-which are optimized for MAP decoding performance- were shown to achieve excellent BP decoding performance in both the waterfall and the error-floor region, thanks to the threshold saturation. However, the BP decoding performance of these spatially coupled codes suffer from a high error-floor at a moderate to short code block length.BP and MAP decoding thresholds of TCs on a binary erasure channel (BEC) have previously been investigated via the DE analysis. The capacity achieving SC-TCs were determined, where the underlying TCs were optimized for the BP and MAP performance. The TCs ensembles, parallel concatenated codes, serially concatenated codes, braided convolutional codes, and hybrid concatenated codes, with varying component convolutional codes strengths were considered in these investigations.This thesis focuses on investigating the BP decoding performance of SC-TCs- which were earlier investigated for the BEC- on an additive white Gaussian noise (AWGN) channel. Furthermore, the problem of high error-floor of SC-TCs for short to moderate block lengths is investigated and addressed with a design of an optimized convlutional permutor in constructing the SC-TCs. Finally, the connection of the TCs and the LDPC codes is explored by introducing a family of convolutional codes (CC) based generalized LDPC codes (GLDPCs). These research areas are summarized under the following three topics.In the first topic, we have computed the iterative decoding thresholds of SC-TCs on the AWGN channel via the Monte Carlo density evolution (MC-DE) methods. The MC-DE methods are time consuming, which has motivated us to introduce an efficient alternative that predicts the AWGN thresholds of SC-TCs with the knowledge of their BEC thresholds. The results show that the estimated thresholds via the MC-DE method and the predicted thresholds are very close for the capacity achieving randomly punctured SC-TCs. For the high rate uncoupled TCs, which are obtained by randomly puncturing their mother code, the predicted thresholds are improved by incorporating the estimated AWGN threshold of the mother code ensemble into the threshold prediction method.In the second topic, we have introduced the design of a single block-wise periodic time-varying convolutional permutor to construct the SC-TCs. The convolutional permutor is designed by applying the unwrapping procedure to an optimized block permutor, which optimize the bit error rate (BER) performance of a TC in an error-floor region. We showed that a convolutional permutor obtained via the unwrapping procedure inherits the properties of its parent permutor. Due to this reason, the BER performance of block-wise periodically time-varying convolutional permutor based SC-SCCs does not suffer from a high error-floor problem at short block lengths, which was demonstrated through the simulation results.In the third topic, we have introduced the families of regular and irregular CC-GLDPCs. The CC-GLDPCs enabled us to connect TCs and LDPC codes in terms of their graph structures. The BEC thresholds and the minimum distance properties of the regular CC-GLDPCs were compared to the regular LDPC codes. Furthermore, we performed an exhaustive grid search using the BEC thresholds of the class of CC-GLDCPs, and determined the design configurations of optimized CC-GLDPCs. The results suggest that, for regular graphs, it is possible to find a sparser CC-GLDPCs than the LDPC codes at the expense of a slightly negligible loss in the performance. Furthermore, the BP optimized CC-GLDPC is observed to have a better BP and MAP thresholds than the turbo codes on the BEC.
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Shu Lin, H. Lyne · IEEE Transactions on Information Theory · 1967
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Kohei Yamauchi, Hiroyuki Kobayashi · IECON 2020 The 46th Annual Conference of the IEEE Industrial Electronics Society · 2020
The authors aim to embed arbitrary information in arbitrary images and restore them using CNN. To achieve this goal, we propose a model consisting of two CNNs with different roles. In the proposed method, it is used as an information medium for embedding a QR code. The QR code error correction function is expected to restore the embedded information without error. Existing research has shown that embedding a QR code in a sharp color image does not restore the QR code correctly. This paper modified the CNN configuration to address this issue. The authors hope this technology can be used to integrate QR codes into human living space and hide information without upset. We learned how to embed a QR code image in a color image using the CNN model proposed this time. As a result, the authors were able to embed the QR code image without degrading the quality of the input color image. Current methods have drawbacks. Blur the image with the embedded QR code. Then, there is a problem that the embedded QR code cannot be restored. We will solve this problem in the future.
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Jun Jin Kong, Keshab K. Parhi · SHILAP Revista de lepidopterología · 2003
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Audrey Tixier · arXiv (Cornell University) · 2015
We give here an efficient algorithm for recovering the block interleaver and the convolutional code when several noisy interleaver codewords are given. This method applies to any interleaver, structured or not and computes in a first step low weight parity-check equations of the interleaved convolutional code. Then a graph representing how these parity-check equations intersect is used to recover at the same time the block interleaver and the convolutional code.
Cited by 15Open access
Scott, Cory, Mjolsness, Eric J · Figshare · 2020
This folder contains the software needed to reproduce the dataset generation and machine learning experiments in "Graph Prolongation Convolutional Networks". Each subfolder covers one experiment, and each has its own readme which includes a list of software dependencies with versions. <br>
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Yang Zhong-li · 2004
This paper presents a project about infraframe convolutional interleaving encoding of block code based on convolutional interleaving encoding of block code. The error-correcting performance of this coding scheme is disscussed by an example.
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Scott, Cory, Mjolsness, Eric J · IOP Publishing · 2020
This folder contains the software needed to reproduce the dataset generation and machine learning experiments in "Graph Prolongation Convolutional Networks". Each subfolder covers one experiment, and each has its own readme which includes a list of software dependencies with versions. <br>
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Yeu-Horng Shiau, Pei‐Yin Chen, Hung‐Yu Yang et al. · 2010
In this paper, an efficient VLSI architecture for convolutional code decoding algorithm is presented. This algorithm locates all erroneous segments of the received sequence and then applies our proposed decoder to these segments only. Besides, the clock-gating technique is used to disable the non-working registers of our design to further reduce the power consumption efficiently with no bit error rate (BER) degradation. Experimental calculations indicate that our design yields more power reduction than the conventional Viterbi decoder.
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Fen Mao · 1996
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Chen, Junran, Manivanan, Manjula, Kollmeyer, Phillip J. · Borealis · 2023
The provided code files are utilized to construct a convolutional neural network (CNN)-based state of health (SOH) estimator using data from Samsung 30T cylindrical 21700 cells. These files encompass essential functions: 1) Preprocessing of original data, including normalization and data splitting, 2) Training the CNN-based SOH estimator, and 3) Evaluating performance and generating result plots for the CNN-based SOH estimator. The comprehensive functionality of these files, as well as detailed discussion of results, are extensively covered in the IEEE Xplore publication titled "A Convolutional Neural Network for Estimation of Lithium-Ion Battery State-of-Health during Constant Current Operation," and supplemented by the accompanying user guide "CNN based SOH estimation code - Users Guide.pdf". The battery aging data used is also open source: “Fifteen minute fast charge aging dataset - Samsung 30T cells”, Borealis Data, 2023. https://doi.org/10.5683/SP3/UYPYDJ
Cited by 1Open access
한군영 · The Royal Society of Chemistry’s Journals, Books and Databases (The Royal Society of Chemistry) · 2021
With the rapid development of Internet technology, information security has become an important means of maintaining social and economic development. In recent years, large-scale cyber attacks have emerged one after another, seriously damaging personal privacy and economic interests. At the same time, the emergence of advanced attack modes represented by APT has caused huge potential threats to social infrastructure, national public service departments, and military scientific and technologicalorganizations. From the analysis of existing attack methods, it can be seen that the variants of malicious code and zero-day vulnerabilities have become one of the most urgent issues facing information security. In particular, the massive amount of network information and malicious code self-protection technology make traditional anti-virus detection systems based on manual analysis encounter unprecedented challenges. Therefore, the recognition of malicious code based on convolutional neural network has become one of the hot spots in the field of information security. \nThis paper mainly focuses on four aspects of malicious code analysis technology: automated feature extraction technology, malicious code detection technology, user-to-end testing, and feature value testing of malicious code. The main research results are as follows: \n1. Since the sequence feature extraction technology can only analyze malicious code from a single perspective, this paper makes an innovation based on the image feature extraction method, discarding the sequence and replacing the sequence feature with image features. \n2. The machine learning models currently applied to automated malicious code detection technology are mainly divided into shallow learning models and deep learning models. \n3. The user end-to-end test classification is the path through which the user enters the code file to output the model classification result. The single run time is less than 0.1 second. \n4. This paper adopts the random forest algorithm, but the feature value test can be completed for sequence special diagnosis or pixel feature. At the same time, this paper proposes a method of fusing sequence feature and pixel feature, and using random forest for testing. The structure results are all More than 90.
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Mayuri Soni -, Chandrashekhar Deshmukh - · International Journal For Multidisciplinary Research · 2023
The need for trustworthy and efficient digital data transmission and storage systems has increased in recent years. The demand to handle and store digital information has grown in the business sector, the military, and the government as a direct result of the widespread availability of high-speed, large-scale data networks. This requirement must be met in order for the design of these systems to keep up with the rapid pace set by communication and computer technologies. When trying to overcome the variable degradation in real time, one of the most important factors to consider is the dependability of the broadband communication channel. Therefore, the use of convolutional codes and other channel-coding strategies is an essential component of any broadband communication system. DSL, WLAN, and 3G standards all require different configurations of convolutional coding, each of which must achieve a specific level of coding performance despite operating at a unique data rate (constraint length and code rate) Therefore, from the perspective of channel-coding techniques, hardware implementations for the development of an encoder are essential. This encoder should be able to support multiple networks using a reconfigurability approach and should be able to function across a variety of standards. Additionally, flexibility and hardware performance should both be prioritised. This calls for forward error control coding with reconfigurable logic, which provides high-speed, low-power dynamically dedicated hardware architectures under a number of speed/power performance constraints at different time intervals that can function within a variety of channel conditions. The ternary computation system has a number of benefits, the most notable of which are the availability of a high data rate, improved spectral efficiency, enhanced coverage, and lower latency. As a result, there is a growing demand for ternary-based systems that use convolutional encoders as a result of developments in technology
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Lengyel, Attila, van Gemert, Jan, Bruintjes, Robert-Jan et al. · 4TU.ResearchData · 2023
Code corresponding to NeurIPS 2023 conference paper "Color Equivariant Convolutional Networks".<br><strong>Abstract</strong>Color is a crucial visual cue readily exploited by Convolutional Neural Networks (CNNs) for object recognition. However, CNNs struggle if there is data imbalance between color variations introduced by accidental recording conditions. Color invariance addresses this issue but does so at the cost of removing all color information, which sacrifices discriminative power. In this paper, we propose Color Equivariant Convolutions (CEConvs), a novel deep learning building block that enables shape feature sharing across the color spectrum while retaining important color information. We extend the notion of equivariance from geometric to photometric transformations by incorporating parameter sharing over hue-shifts in a neural network. We demonstrate the benefits of CEConvs in terms of downstream performance to various tasks and improved robustness to color changes, including train-test distribution shifts. Our approach can be seamlessly integrated into existing architectures, such as ResNets, and offers a promising solution for addressing color-based domain shifts in CNNs.
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J.W. Modestino, S.Y. Mui · IRE Transactions on Communications Systems · 1976
The performance of short constraint length convolutional codes in conjunction with binary phase-shift keyed (BPSK) modulation and Viterbi maximum likelihood decoding on the classical Rician fading channel is examined in detail. Primary interest is in the bit error probability performance as a function of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">E_{b}/N_{0}</tex> parameterized by the fading channel parameters. Fairly general upper bounds on bit error probability performance in the presence of fading are obtained and compared with simulation results in the two extremes of zero channel memory and infinite channel memory. The efficacy of simple block interleaving in combating the memory of the channel is thoroughly explored. Results include the effects of fading on tracking loop performance and the subsequent impact on overall coded system performance. The approach is analytical where possible; otherwise resort is made to digital computer simulation.
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Maher Kouraichi, Amin Toumi, Abdennaceur Kachouri et al. · 2005
We know that the role of the technique of interleaving in the turbo codes is determining, this is due to the fact that the turbo codes have two (or more) decoder elements concatenated in parallel or serially. Each decoder alone can produce series of erroneous bits which, if not scattered on the entire data frame with an interleaving operation, degrade the performances of the following decoder. What we don't see usually is the use of the interleavers with the convolutional codes which are at the base of the turbo codes. In this paper we will evaluate the effect of interleavers on the performance of error correction in the chain of communication using convolutional codes as error correcting code, we will argue why to use interleaving or not in this category of correcting code.
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Smita Jolania, Ravi Sindal, Ankit Saxena · International Journal of Autonomous and Adaptive Communications Systems · 2025
Polar codes (PC) are the major contender in fifth generation-new radio (5G-NR) for error control in the physical downlink control channel (PDCCH) The work proposes a novel concatenated error correction technique of PC with convolutional codes (CC) and is experimented under 5G simulation constraints. This research paper develops a simulation model of universal filtered multicarrier (UFMC) modulation based massive multiple-input multiple-output (MIMO) technique targeting for short burst transmissions. The UFMC uses sub-band filtering with reduced out-of-band emissions (OOBE) and enhanced spectral efficiency. An analytical framework of the novel PC-CC-UFMC system to effectively correlate the flexible design parameters for different wireless channels is implemented to enhance bit error rate (BER) performance. The results shown in paper, a gain in the required signal to noise ratio (SNR) for same BER is reduced by approximately 5 dB for increase in antenna from 64 to 256.
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Sudharman K. Jayaweera, H. Vincent Poor · 2003
A turbo decoding scheme for a noncoherent, unitary space-time modulated communication system employing an FEC convolutional code is proposed. The channel is assumed to be Rayleigh fading with neither the transmitter nor the receiver knowing the channel coefficients. The convolutional encoder is applied to the information symbols before performing unitary spacetime coding. Treating the combination of convolutional code and the unitary space-time code as a serially concatenated turbo code, it is shown that the performance can be improved by iterative decoding. Simulation results suggest that the iterative decoder can offer significant performance gain over conventional, non-iterative methods and also can help close the performance gap between coherent (e.g. Alamouti type) and non-coherent techniques by a significant margin.
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Ying Cui, Zhanji Wu, Xiang Gao et al. · 2012
In digital communications, 90 or 180 degree phase ambiguity between the receiver and transmitter carrier is a serious problem for the coherent demodulation. To remove their phase ambiguity, differential quadrature phase shift keying (DQPSK) was proposed with the cost of a remarkable 2.4 dB performance degradation. Based on the iterative decoding (ID) scheme, an efficient joint convolutional code (CC)-coded DQPSK method is proposed to close the gap between quadrature phase shift keying (QPSK) and DQPSK. Using the extrinsic information transfer (EXIT) chart technique, we unveil that the low-complexity convolutional codes outperform the high-complexity Turbo codes for the ID scheme. Simulation results turn out that the proposed scheme can overcome the error-floor effect, and achieve almost 3.54 dB and 0.9 dB signal-to-noise ratio (SNR) gain compared with the non-iterative CC at 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-5</sup> Bit Error Rate (BER)and iterative Turbo schemes at 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-7</sup> BER, respectively.
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