Search

Your search keyword '"Decoding methods"' showing total 13 results
Start Over Descriptor "Decoding methods" Language french
13 results on '"Decoding methods"'

1. Decoding patent examination services

Author

Lluis Gimeno-Fabra and Bruno van Pottelsberghe de la Potterie

Subjects
Typology, Public information, Economie internationale, Knowledge management, business.industry, Computer science, InformationSystems_INFORMATIONSYSTEMSAPPLICATIONS, 05 social sciences, Intellectual property, Systèmes économiques comparés, Economie industrielle, Management of Technology and Innovation, 0502 economics and business, Key (cryptography), 050207 economics, business, General Economics, Econometrics and Finance, 050203 business & management, Decoding methods
Abstract

This paper puts forward a new methodology to characterize and compare the examination practice of patent offices. The methodology codifies public information into a typology of chronological key ex...

Published
2020

2. Acceleration of low density parity check code (LDPC) decoding by successive overrelaxations

Author

Yannick Saouter, Lab-STICC_IMTA_CACS_IAS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT), Département Electronique (IMT Atlantique - ELEC), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)

Subjects
Decoding algorithm, LDPC codes, Computer science, 020208 electrical & electronic engineering, Process (computing), 020206 networking & telecommunications, 02 engineering and technology, Data_CODINGANDINFORMATIONTHEORY, Belief propagation, [SPI.TRON]Engineering Sciences [physics]/Electronics, Acceleration, 0202 electrical engineering, electronic engineering, information engineering, Code (cryptography), Electrical and Electronic Engineering, Low-density parity-check code, Algorithm, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods, Parity bit, Computer Science::Information Theory
Abstract

International audience; Belief propagation and variants are the usual decoding algorithms for low density parity check codes. In this paper, successive overrelaxations are applied to increase convergence speed of the decoding process. Performances are reported and improvements over reference algorithms are observed. This technique is also compatible with high speed parallel group decoding involved in modern standards like DVB-S2.

Published
2018
Full Text
View/download PDF

3. Optimized Short-Length Rate-Adaptive LDPC Codes for Slepian-Wolf Source Coding

Author

Fangping Ye, Karine Amis, Elsa Dupraz, Zeina Mheich, Département Signal et Communications (IMT Atlantique - SC), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT), Lab-STICC_IMTA_CACS_COM, Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL), and Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique)

Subjects
Channel code, Source code, LDPC codes, Computer science, media_common.quotation_subject, 05 social sciences, 050209 industrial relations, Short length, Source coding, 0502 economics and business, Low-density parity-check code, Algorithm, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, 050203 business & management, Decoding methods, media_common
Abstract

International audience; This paper proposes a new construction of rate-adaptive coding schemes based on Low Density Parity Check (LDPC) codes for Slepian Wolf source coding. Unlike standard rate-adaptive source coding schemes, the code construction we propose is based on finite-length code design tools that permit to greatly improve the decoding performance at short to moderate length. In particular, our method permits to limit the number of short cycles in the codes at all rates of interest, and to avoid eliminating some source bits from the code constraints. The proposed method shows a performance improvement of up to an order of magnitude at almost all the considered rates compared to the standard LDPCA construction.

Published
2018
Full Text
View/download PDF

4. Performance of Taylor-Kuznetsov memories under timing errors

Author

Elsa Dupraz, Bane Vasic, David Declercq, Lab-STICC_IMTA_CACS_COM, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-Institut Mines-Télécom [Paris] (IMT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL), Département Signal et Communications (IMT Atlantique - SC), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Department of Electrical and Computer Engineering [Tucson] (ECE), University of Arizona, Equipes Traitement de l'Information et Systèmes (ETIS - UMR 8051), and Ecole Nationale Supérieure de l'Electronique et de ses Applications (ENSEA)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)

Subjects
Computer science, Computation, 020208 electrical & electronic engineering, Monte Carlo method, Static timing analysis, [MATH.MATH-IT]Mathematics [math]/Information Theory [math.IT], 020206 networking & telecommunications, 02 engineering and technology, Parallel computing, Power (physics), Memory architecture, 0202 electrical engineering, electronic engineering, information engineering, Code (cryptography), Transient (computer programming), Algorithm, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods
Abstract

International audience; Lowering the power supply of a circuit can induce transient errors in the memory cells and timing errors in the computation units. In this paper, we consider the Taylor-Kuznetsov (TK) memory architecture with transient errors in the memory cells and with timing errors in the correction circuit. We provide a theoretical analysis of the performance of TK memories under transient errors and timing errors. Our study is based on the analysis of the computation trees of the equivalent Gallager B decoders with and without timing errors. As a main result, we show that as the number of iterations goes to infinity, the error probability of the decoder with timing errors converges to the error probability of the decoder without timing errors. Monte Carlo simulations confirm this result even for moderate code lengths.

Published
2017
Full Text
View/download PDF

5. Towards a Minimal Representation of Affective Gestures (Extended Abstract)

Author

Glowinski, Donald, Mortillaro, Marcello, Scherer, Klaus R., Dael, Nele, Volpe, Gualtiero, and Camurri, Antonio

Subjects
Multimodal search, ddc:128.37, Human–computer interaction, Speech recognition, Feature extraction, Eye tracking, Valence (psychology), Psychology, Decoding methods, Arousal, Gesture, Visualization
Abstract

How efficiently decoding affective information when computational resources and sensor systems are limited? This paper presents a framework for analysis of affective behavior starting with a reduced amount of visual information related to human upper-body movements. The main goal is to individuate a minimal representation of emotional displays based on non-verbal gesture features. The GEMEP (Geneva multimodal emotion portrayals) corpus was used to validate this framework. Twelve emotions expressed by ten actors form the selected data set of emotion portrayals. Visual tracking of trajectories of head and hands was performed from a frontal and a lateral view. Postural/shape and dynamic expressive gesture features were identified and analyzed. A feature reduction procedure was carried out, resulting in a four-dimensional model of emotion expression, that effectively classified/grouped emotions according to their valence (positive, negative) and arousal (high, low). These results show that emotionally relevant information can be detected/measured/obtained from the dynamic qualities of gesture. The framework was implemented as software modules (plug-ins) extending the EyesWeb XMI Expressive Gesture Processing Library and was tested as a component for a multimodal search engine in collaboration with Google within the EU-ICT I-SEARCH project.

Published
2015

6. A low-complexity soft-decision decoding architecture for the binary extended Golay code

Author

P. Adde, R. Le Bidan, Lab-STICC_TB_CACS_IAS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance ( Lab-STICC ), École Nationale d'Ingénieurs de Brest ( ENIB ) -Université de Bretagne Sud ( UBS ) -Université de Brest ( UBO ) -Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques ( IBNM ), Université de Brest ( UBO ) -Université européenne de Bretagne ( UEB ) -ENSTA Bretagne-Institut Mines-Télécom [Paris]-Centre National de la Recherche Scientifique ( CNRS ) -École Nationale d'Ingénieurs de Brest ( ENIB ) -Université de Bretagne Sud ( UBS ) -Université de Brest ( UBO ) -Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques ( IBNM ), Université de Brest ( UBO ) -Université européenne de Bretagne ( UEB ) -ENSTA Bretagne-Institut Mines-Télécom [Paris]-Centre National de la Recherche Scientifique ( CNRS ), Département Electronique ( ELEC ), Université européenne de Bretagne ( UEB ) -Télécom Bretagne-Institut Mines-Télécom [Paris], Lab-STICC_TB_CACS_COM, Télécom Bretagne (devenu IMT Atlantique), Ex-Bibliothèque, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Département Electronique (ELEC), and Université européenne de Bretagne - European University of Brittany (UEB)-Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne

Subjects
Computer science, Concatenated error correction code, Decoder architecture, 020206 networking & telecommunications, 02 engineering and technology, Sequential decoding, [SPI.TRON] Engineering Sciences [physics]/Electronics, 020202 computer hardware & architecture, [SPI.TRON]Engineering Sciences [physics]/Electronics, [ SPI.TRON ] Engineering Sciences [physics]/Electronics, Computational complexity, Ternary Golay code, Binary Golay code, Systematic short block coe, Re-encoding, Cyclic code, 0202 electrical engineering, electronic engineering, information engineering, Golay code, Constant-weight code, Low-density parity-check code, Algorithm, Decoding methods, Computer Science::Information Theory
Abstract

International audience; The (24, 12, 8) extended binary Golay code is a well-known rate-1/2 short block-length linear error-correcting code with remarkable properties. This paper investigates the design of an efficient low-complexity soft-decision decoding architecture for this code. A dedicated algorithm is introduced that takes advantage of the code’s properties to simplify the decoding process. Simulation results show that the proposed algorithm achieves close to maximum-likelihood performance with low computational cost. The decoder architecture is described, and VLSI synthesis results are presented.

Published
2012

7. A turbo decoder included in a multi-user detector: a solution to be retained

Author

Sylvie Kerouedan, Patrick Adde, Samir Saoudi, Makram Touzri, Lab-STICC_TB_CACS_IAS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (UMR 3192) (Lab-STICC), Université européenne de Bretagne - European University of Brittany (UEB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université européenne de Bretagne - European University of Brittany (UEB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Département Electronique (ELEC), Université européenne de Bretagne - European University of Brittany (UEB)-Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne, Lab-STICC_TB_CACS_COM, Département Signal et Communications (SC), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (UMR 3192) ( Lab-STICC ), Université européenne de Bretagne ( UEB ) -Université de Bretagne Sud ( UBS ) -Université de Brest ( UBO ) -Institut Brestois du Numérique et des Mathématiques ( IBNM ), Université de Brest ( UBO ) -Télécom Bretagne-Institut Mines-Télécom [Paris]-Centre National de la Recherche Scientifique ( CNRS ) -Université européenne de Bretagne ( UEB ) -Université de Bretagne Sud ( UBS ) -Université de Brest ( UBO ) -Institut Brestois du Numérique et des Mathématiques ( IBNM ), Université de Brest ( UBO ) -Télécom Bretagne-Institut Mines-Télécom [Paris]-Centre National de la Recherche Scientifique ( CNRS ), Département Electronique ( ELEC ), Université européenne de Bretagne ( UEB ) -Télécom Bretagne-Institut Mines-Télécom [Paris], Département Signal et Communications ( SC ), and Institut Mines-Télécom [Paris]-Télécom Bretagne-Université européenne de Bretagne ( UEB )

Subjects
Computer science, Real-time computing, 050801 communication & media studies, [ SPI.SIGNAL ] Engineering Sciences [physics]/Signal and Image processing, CDMA, Turbo equalizer, 0508 media and communications, 0502 economics and business, Turbo code, Turbocode, Multi-user detection, business.industry, Code division multiple access, 05 social sciences, Detector, Rake, Turbo-CDMA, [ SPI.TRON ] Engineering Sciences [physics]/Electronics, [SPI.TRON]Engineering Sciences [physics]/Electronics, Single antenna interference cancellation, 050211 marketing, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Computer hardware, Decoding methods, UMTS frequency bands
Abstract

This paper deals with the presentation of different multi-user detectors in the Universal Mobile Telecommunications System (UMTS) context. The challenge is always to optimize the compromise between performance and complexity. Compared with the solution commonly used today, the rake detector, successive interference cancellation (SIC) detector has better performance despite its higher complexity. Our innovative solution proposes joining detector and channel turbo decoder to get a significant gain in terms of performance. Furthermore, when detection and decoding are implemented in a single function, complexity does not increase much.

Published
2010
Full Text
View/download PDF

8. Décodage EM du code de Tardos pour le fingerprinting

Author

Teddy Furon, Caroline Fontaine, Ana Charpentier, Digital image processing, modeling and communication (TEMICS), Institut de Recherche en Informatique et Systèmes Aléatoires (IRISA), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Inria Rennes – Bretagne Atlantique, and Furon, Teddy

Subjects
Theoretical computer science, Iterative method, Computer science, [INFO.INFO-TS] Computer Science [cs]/Signal and Image Processing, Data_MISCELLANEOUS, 02 engineering and technology, Tracing, Computer security, computer.software_genre, Information protection policy, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Traitor tracing, Expectation–maximization algorithm, 0202 electrical engineering, electronic engineering, information engineering, Electrical and Electronic Engineering, Digital watermarking, ComputingMilieux_MISCELLANEOUS, [SPI.SIGNAL] Engineering Sciences [physics]/Signal and Image processing, 020206 networking & telecommunications, [INFO.INFO-TI] Computer Science [cs]/Image Processing [eess.IV], [INFO.INFO-TI]Computer Science [cs]/Image Processing [eess.IV], Collusion, 020201 artificial intelligence & image processing, computer, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods
Abstract

This paper presents our recent work on multimedia fingerprinting, also known as traitor tracing. We focus on deriving a better accusation process for the well known Tardos codes. It appears that Tardos orginal decoding is very conservative: its performances are guaranteed whatever the collusion strategy. Indeed, major improvements stem from the knowledge of the collusion strategy. Therefore, this paper investigates how it is possible to learn and adapt to the collusion strategy. Our solution is based on an iterative algorithm a la EM, where a better estimation of the collusion strategy yields a better tracing of the colluders, which in return yields a better estimation of the collusion strategy etc.

Published
2009

9. On the use of Reed-Solomon codes in Space-Time coding

Author

Karine Amis, D. Leroux, M. Lalam, Département Signal et Communications (SC), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), and Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB)

Subjects
Block code, Interleaving, Computer science, Real-time computing, 050801 communication & media studies, 02 engineering and technology, Data_CODINGANDINFORMATIONTHEORY, STBCs, RS, Space–time block code, 0508 media and communications, Reed–Solomon error correction, 0202 electrical engineering, electronic engineering, information engineering, Channel code, Error floor, Concatenated error correction code, 05 social sciences, 020206 networking & telecommunications, Code rate, Linear code, SEW, Space–time code, Algorithm, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods, Communication channel
Abstract

International audience; In this paper, we present an original use of Reed-Solomon (RS) codes as space-time block codes (STBCs) and compare them to orthogonal STBCs (OSTBCs). Due to their symbol structure, they can have a representation close to that of an STBC. RS codes are admittedly more complex to decode as they have no orthogonal properties. However, they offer much higher coding rates. In addition, a wide range of these codes can be easily generated. To decode them, we have developed a new algorithm using a sliding encoding-window (SEW), which is combined with the decoding-based Chase algorithm. We compare the RS(15,7) code to the Alamouti one, both having an equivalent coding rate. Its performance compared to Alamouti gets better as the receive diversity increases. Moreover, RS codes do not require the channel to remain constant over the code duration. In fact, they offer better results if the channel changes rapidly, which can be obtained virtually by introducing interleaving

Published
2005

10. Blind detection of interleaver parameters

Author

Sebastien Houcke, G. Sicot, Département Signal et Communications (SC), Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB), and Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT)

Subjects
Theoretical computer science, Interleaving, Computer science, 05 social sciences, 050801 communication & media studies, 020206 networking & telecommunications, 02 engineering and technology, Data_CODINGANDINFORMATIONTHEORY, Time diversity, Binary symmetric channel, 0508 media and communications, 0202 electrical engineering, electronic engineering, information engineering, Turbo code, Bit error rate, Error detection and correction, Algorithm, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods, Computer Science::Information Theory
Abstract

International audience; Interleaving is a key component of many digital communication systems involving error correction schemes. It provides a form of time diversity to guard against bursts of errors. Recentlty, interleavers have become an even more integral part of the code design itself, if we consider for example turbo and turbo-like codes. In a non-cooperative context, such as passive listening, it is a challenging problem to estimate the interleaver parameters. In this paper, we propose an algorithm that allows us to estimate the parameters of the interleaver at the output of a binary symmetric channel and to locate the code-words in the interleaved block. This gives us some clues about the interleaving function used.

Published
2005

11. Iterative decoding of product codes with a priori information over a Gaussian channel forstill image transmission

Author

A. Elbaz, B. Solaiman, R. Ryndiah, O. Ait Sab, Département Signal et Communications (SC), Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT), and Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB)

Subjects
Block code, Theoretical computer science, Computer science, Codebook, List decoding, 020206 networking & telecommunications, Data compression ratio, 02 engineering and technology, Sequential decoding, Serial concatenated convolutional codes, Data_CODINGANDINFORMATIONTHEORY, Coding gain, 0202 electrical engineering, electronic engineering, information engineering, Turbo code, 020201 artificial intelligence & image processing, Encoder, Algorithm, 16-QAM, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods, Quadrature amplitude modulation, BCH code, Communication channel
Abstract

International audience; In this paper we propose an optimized transmission system for still images. This system comprises a VQ source encoder with a compression rate of 9. The source data is encoded using a BCH product code and mapped on a 16-QAM constellation. The codebook and channel encoder have been optimized to minimize distortion in presence of transmission errors. We use a new joint source-channel turbo decoding algorithm of the product code. As compared to classical channel decoding algorithms (soft decoding), we obtain an improvement of 0.7 dB in terms of coding gain for a BER of 10/sup -5/. The PSNR of the received image exhibits an improvement of 11 dB as compared to conventional turbo decoding at low SNRs.

Published
1999

12. Optimized source coding and coded modulation for digital transmission of still images on a noisy channel

Author

O. Aitsab, Ramesh Pyndiah, Basel Solaiman, Département Signal et Communications (SC), Institut Mines-Télécom [Paris] (IMT)-Télécom Bretagne-Université européenne de Bretagne - European University of Brittany (UEB), and Université européenne de Bretagne - European University of Brittany (UEB)-Télécom Bretagne-Institut Mines-Télécom [Paris] (IMT)

Subjects
Channel (digital image), Speech recognition, 05 social sciences, Vector quantization, 050801 communication & media studies, 020206 networking & telecommunications, 02 engineering and technology, Digital transmission, Channel, Peak signal-to-noise ratio, 0508 media and communications, Still images, 0202 electrical engineering, electronic engineering, information engineering, Discrete cosine transform, Algorithm, Encoder, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Decoding methods, Transform coding, Mathematics, Data transmission
Abstract

International audience; In this paper, we propose a complete transmission system for still images which minimizes the distortion introduced by residual transmission errors. This system comprises a source encoder combining DCT (Discrete Cosine Transform) and VQ (Vector Quantization). The compression rate is equal to 16.7 for an average PSNR (Peak Signal to Noise Ratio) of 29.2 dB. The data is then encoded by a BCH(63,57,3) block code and is mapped on a 64-QAM constellation. The parameters of the code book and channel encoder have been optimized for 64-QAM. For channel decoding, we use maximum likelihood sequence decoding. The PSNR of the reconstructed image in the receiver is equal to 28.6 dB for a channel SNR of I1 dB. This represents a very small degradation of the PSNR (0.6 dB) in presence of a SER (Symbol Error Rate) of 10% at the input of the receiver

Published
1998

13. Apport d'une segmentation statistique du signal de parole dans un système de décodage acoustico phonétique basé sur les connaissances

Author

Régine André-Obrecht and Nathalie Parlangeau

Subjects
business.industry, Computer science, General Physics and Astronomy, Pattern recognition, 01 natural sciences, 010305 fluids & plasmas, Knowledge-based systems, Hybrid system, [PHYS.HIST]Physics [physics]/Physics archives, 0103 physical sciences, A priori and a posteriori, Preprocessor, Segmentation, Artificial intelligence, Transcription (software), business, Divergence (statistics), Decoding methods
Abstract

In a speech labelling system, traditionnaly the first stage conists in the transcription of the continuous acoustic signal into a series of discrete elementaries units. This stage called Acoustic-Phonetic decoding unrolls three phasis: parametrisarion, segmentation and identification. All the systems do not use the module of segmentation stricktly speaking. For those that use it, they differ from one another in their strategy of segmentation. So we distisguish two different approachs, one is based on an a posteriori segmentation an the other on an a priori one. This paper presents an automatic phoneme recognition system based on a preprocessing segmentation algorithm called the Divergence method. The study of these performances got by Divergence and those obtained by a knowledge based system (SED) where the segmentation is an a posteriori result, has brought us to propose an hybrid system named the SED -Divergence method, using the advantages of the two methods. We asser these systems by integraring them into a labelling process

Published
1994
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results