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Impact of code rate and constraint length variation on qualitative performance of OIDMA system with random inter-leaver

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OPTIK 2020年 202卷

作者： Maurya, Ajay Kumar Prakash, Ravi Sriwas, S. K. Kumar, Pramod Singh, R. K. Veer Bahadur Singh Purvanchal Univ Jaunpur UNS Inst Engn & Technol Dept Elect & Instrumentat Engn Jaunpur Uttar Predesh India Veer Bahadur Singh Purvanchal Univ UNS Inst Engn & Technol Dept Elect & Commun Engn Jaunpur 222003 Uttar Pradesh India Bundelkhand Inst Engn & Technol Dept Elect & Commun Engn Jhansi 284128 Uttar Pradesh India Manipal Acad Higher Educ Manipal Inst Technol Dept Elect & Commun Engn Manipal 576104 Karnataka India Kamla Nehru Inst Technol Sultanpur Dept Elect Engn Sultanpur 228118 Uttar Pradesh India

The impact of the code rate and constraint length on the qualitative performance of optical interleave division multiple access (OIDMA) system is analyzed. The various topologies of convolution encoder design have implemented by considering various shift registers as well as several Ex-OR gates to achieve the performance. Further, the bit error rate (BER) calculated for a different possible combination of random inter-leaver. The BER increases with the number of users, whereas it decreases with the code rate and constraint length.

关键词： OIDMA convolutional coding Network topology Random inter-leaver Constraint length

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Bahl-Cocke-Jelinek-Raviv decoding algorithm applied to the three-user binary adder channel

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IET COMMUNICATIONS 2015年第7期9卷 897-902页

作者： Alcoforado, Maria de Lourdes M. G. Oliveira, Mariana C. C. da Rocha, Valdemar C., Jr. Univ Pernambuco UPE Commun Grp GCOM Telecommun Lab LABTEL BR-50750470 Recife PE Brazil Univ Fed Pernambuco Commun Res Grp CODEC Dept Elect & Syst BR-50740550 Recife PE Brazil

The Bahl-Cocke-Jelinek-Raviv (BCJR) algorithm is a well-known maximum a posteriori probability decoding algorithm which has been proposed earlier for point to point communication applications, employing block codes or convolutional codes and turbo codes. This study describes an application of the BCJR algorithm for decoding the output of a multiple-access channel called the noisy three-user binary adder channel, in the presence of additive white Gaussian noise. The computer simulation results are presented for the overall coding performance in terms of bit error rate against signal-to-noise ratio.

关键词： Multiple Access Channel Block codes AWGN COMMUNICATIONS APPLICATION adders Access Channels Worm gears Maximum a posteriori estimation a posteriori probability decoding algorithm Simulation results convolutional coding

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An artificial neural net Viterbi decoder

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IEEE TRANSACTIONS ON COMMUNICATIONS 1996年第2期44卷 165-171页

作者： Wang, XA Wicker, SB School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA USA

The Viterbi algorithm is a maximum likelihood means for decoding convolutional codes and has thus played an important role in applications ranging from satellite communications to cellular telephony, In the past, Viterbi decoders have usually been implemented using digital circuits. The speed of these digital decoders is directly related to the amount of parallelism in the design. As the constraint length of the code increases, parallelism becomes problematic due to the complexity of the decoder. In this paper an artificial neural network (ANN) Viterbi decoder is presented. The ANN decoder is significantly faster than comparable digital-only designs due to its fully parallel architecture. The fully parallel structure is obtained by implementing most of the Viterbi algorithm using analog neurons as opposed to digital circuits. Several modifications to the ANN decoder are considered, including an analog/digital hybrid design that results in an extremely fast and efficient decoder. The ANN decoder requires one-sixth the number of transistors required by the digital decoder. The connection weights of the ANN decoder are either +1 or -1, so weight considerations in the implementation are eliminated. This, together with the design's modularity and local connectivity, makes the ANN Viterbi decoder a natural fit for VLSI implementation. Simulation results are provided to show that the performance of the ANN decoder matches that of an ideal Viterbi decoder.

关键词： Viterbi algorithm decoders parallelism constraint length digital circuits Viterbi decoders convolutional coding Satellite communication

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Parameter optimization and simulated performance of a DVB-T digital television broadcasting system

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IEEE TRANSACTIONS ON BROADCASTING 1998年第1期44卷 131-138页

作者： Armada, AG Bardon, B Calvo, M Univ Politecn Madrid Grp Radiac Dpto SSR Madrid Spain

A prototype of a Digital Television Terrestrial Broadcasting System has been implemented according to the European DVB-T standard. The first step in the construction of this prototype involved parameter optimization via simulation. This paper presents the optimization process of the system parameters and the final achieved BER performance. Important design aspects such as interleaving, convolutional puncturing codes, Viterbi decoding, pilot-based channel correction and optimal pilot power are considered. The DVB-T standard offers some suggested values of the C/N ratio needed to achieve the desired BER requirements in the receiver. However, they have been obtained assuming ideal channel correction and synchronization. Simulation results are provided here in non-ideal conditions.

关键词： Viterbi decoding convolutional codes digital television error statistics optimisation television broadcasting television receivers television standards television transmitters video coding BER C/N ratio DVB-T digital television broadcasting system Europe television broadcasting Television Television receivers Digital television Parameter optimization pilot power Video coding Viterbi decoding terrestrial digital video broadcasting Broadcasting system convolutional coding television standards

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ERROR-PROBABILITY FOR REPEAT REQUEST SYSTEMS WITH convolutional-CODES

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IEEE TRANSACTIONS ON INFORMATION THEORY 1993年第5期39卷 1680-1684页

作者： KUDRYASHOV, BD Department of Automatic Control Systems St. Petersburg Institute of Aviation Instrument Making Saint Petersburg Russia

A new decoding algorithm based on the modified Viterbi algorithm for repeat request systems is considered. A new asymptotic error probability bound is derived. It is shown that the error exponent for convolutional coding can be related to the exponent for block coding by a graphical method known as inverse concatenation construction.

关键词： REPEAT REQUEST SYSTEM convolutional coding VITERBI ALGORITHM ERROR PROBABILITY EXPONENT

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LIMITING ERROR PROPAGATION IN VITERBI DEcoding OF convolutional-CODES

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IEEE TRANSACTIONS ON INFORMATION THEORY 1989年第6期35卷 1295-1299页

作者： LEONARD, DA RODGER, CA Department of Algebra Combinatorics and Analysis Aubum University Auburn AL USA

The problem of avoiding infinite error propagation in noncatastrophic convolutional codes when using a truncated Viterbi decoder is considered. A truncation length tau is defined in terms of walks in the state diagram. The truncation length guarantees that, in the presence of a sufficiently long guard space, a truncated Viterbi decoder will always recover from any error event. This value of tau is the theoretically smallest possible truncation length.

关键词： Error propagation Viterbi decoders Cutoffs walking convolutional coding

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Pilot symbol assisted BPSK on Rayleigh fading channels with diversity:: Performance analysis and parameter optimization

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IEEE TRANSACTIONS ON COMMUNICATIONS 1998年第12期46卷 1560-1563页

作者： Schramm, P Müller, RR Univ Erlangen Nurnberg Telecommun Lab D-90411 Erlangen Germany

In this letter, the loss due to imperfect channel estimation is derived for pilot symbol assisted binary phase-shift keying (BPSK) on fading channels with diversity, The presented approach, which holds for both narrow-band and spread spectrum communication, further provides an analytical optimization of pilot symbol spacing. The loss due to channel estimation is demonstrated to be low if the maximum Doppler frequency is significantly less than the bit rate.

关键词： channel estimation code-division multiple access convolutional coding phase-shift keying Rayleigh fading channel spread spectrum

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AN EFFICIENT MAXIMUM-LIKELIHOOD DEcoding ALGORITHM FOR GENERALIZED TAIL BITING convolutional-CODES INCLUDING QUASICYCLIC CODES

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IEEE TRANSACTIONS ON COMMUNICATIONS 1989年第8期37卷 875-879页

作者： WANG, Q BHARGAVA, VK Department of Electrical and Computer Engineering University of Victoria Victoria BC Canada

The complexity of the algorithm is shown to be asymptotically equal to that of the Viterbi algorithm and is very close for practical noisy channels. The latter is shown by means of computer simulation. The algorithm can be applied directly in an environment where soft-decision decoding is required or preferred. However, depending on the environment, some simplifications may be possible and/or necessary, resulting in suboptimal algorithms. Codes suitable for use with the algorithm should have short total memory length.

关键词： Environments maximum likelihood decoding soft-decision decoding maximum likelihood algorithms convolutional coding tail biting Viterbi algorithm Codes

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Improving RCPC Codes in Rate-Adaptive Optical Wireless Communications Systems

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WIRELESS PERSONAL COMMUNICATIONS 2013年第2期69卷 879-889页

作者： Maria Garrido-Balsells, Jose Jurado-Navas, Antonio Castillo-Vazquez, Miguel Puerta-Notario, Antonio Univ Malaga Dept Commun Engn E-29071 Malaga Spain

In this paper, we analyse the performance of rate-compatible punctured convolutional (RCPC) codes for wireless optical communications systems. For these environments, a novel hybrid RCPC coding scheme with a modified puncturing matrix is proposed based on the insertion of variable silence periods. This transmission technique achieves better bit-error rate results than conventional RCPC and convolutional coding schemes, in agreement to the obtained increase in the peak-to-average optical power ratio.

关键词： Optical communications Rate-compatible Punctured convolutional coding Variable silence periods Peak-to-average optical power ratio

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Robust transmission of Jpeg2000 images over noisy channels

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IEEE TRANSACTIONS ON CONSUMER ELECTRONICS 2002年第3期48卷 451-456页

作者： Sanchez, VS Mandal, MK Univ Alberta Edmonton AB Canada

An unequal channel protection technique for JPEG2000 encoded images is proposed The proposed technique takes advantage of the hierarchical organization of the JPEG2000 bit-stream and protects only the most important part of the compressed bit-stream, by means of a rate compatible punctured convolutional code. Both single-quality-layer and multiple-quality-layer compressions are considered The performance of this technique is evaluated under various noisy channel conditions. Simulation results show that the probability of correct decoding the received information and the quality of the reconstructed image are improved by the proposed technique.

关键词： image coding code standards telecommunication standards data compression visual communication noise telecommunication channels image reconstruction convolutional codes robust transmission JPEG2000 images noisy channels hierarchical organi JPEG code standards noisy channel image coding image reconstruction Data compression convolutional coding

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