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Low complexity iterative differential decoding algorithm for multiband UWB communication systems
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作者 金秀峰 毕光国 肖海勇 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期7-11,共5页
Due to not requiring channel state information (CSI) at both the transmitter and the receiver, noncoherent ultra-wideband (UWB) incurs a performance penalty of approximately 3 dB in the required signal to noise ra... Due to not requiring channel state information (CSI) at both the transmitter and the receiver, noncoherent ultra-wideband (UWB) incurs a performance penalty of approximately 3 dB in the required signal to noise ratio (SNR) compared to the coherent case. To overcome the gap, an effective differential encoding and decoding scheme for multiband UWB systems is proposed. The proposed scheme employs the parallel concatenation of two recursive differential unitary space-frequency encoders at the transmitter. At the receiver, two component decoders iteratively decode information bits by interchanging soft metric values between each other. To reduce the computation complexity, a decoding algorithm which only uses transition probability to calculate the log likelihood ratios (LLRs) for the decoded bits is given. Simulation results show that the proposed scheme can dramatically outperform the conventional differential and even coherent detection at high SNR with a few iterations. 展开更多
关键词 multiband UWB multiple-input multiple-output (MIMO) system noncoherent detection group code iterative decoding
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Improved iterative breadth-first detection algorithms for MIMO wireless systems
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作者 郑武 Song Wentao +1 位作者 Zhang Haibin Xu Youyun 《High Technology Letters》 EI CAS 2007年第2期184-188,共5页
A reduced-complexity detection algorithm is proposed, which is applied to iterative receivers for multiple-input multiple-output (MIMO) systems. Unlike the exhaustive search over all the possible trans-mitted symbol... A reduced-complexity detection algorithm is proposed, which is applied to iterative receivers for multiple-input multiple-output (MIMO) systems. Unlike the exhaustive search over all the possible trans-mitted symbol vectors of the optimum maximum a posteriori probability (MAP) detector, the new algo-rithm evaluates only the symbol vectors that contribute significantly to the soft output of the detector. The algorithm is facilitated by carrying out the breadth-first search on a reconfigurable tree, constructed by computing the symbol reliability of each layer based on zero-forcing criterion and reordering the symbols according to the symbol reliabilities. Simulations are presented and the good performance of the new algo-rithm over a quasi-static Rayleigh channel even for relatively small list sizes are proved. 展开更多
关键词 concatenated codes MIMO systems BLAST iterative decoder Turbo codes
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Erasure-Correction-Enhanced Iterative Decoding for LDPC-RS Product Codes 被引量:5
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作者 Weigang Chen Ting Wang +1 位作者 Changcai Han Jinsheng Yang 《China Communications》 SCIE CSCD 2021年第1期49-60,共12页
Low-density parity-check(LDPC)codes are widely used due to their significant errorcorrection capability and linear decoding complexity.However,it is not sufficient for LDPC codes to satisfy the ultra low bit error rat... Low-density parity-check(LDPC)codes are widely used due to their significant errorcorrection capability and linear decoding complexity.However,it is not sufficient for LDPC codes to satisfy the ultra low bit error rate(BER)requirement of next-generation ultra-high-speed communications due to the error floor phenomenon.According to the residual error characteristics of LDPC codes,we consider using the high rate Reed-Solomon(RS)codes as the outer codes to construct LDPC-RS product codes to eliminate the error floor and propose the hybrid error-erasure-correction decoding algorithm for the outer code to exploit erasure-correction capability effectively.Furthermore,the overall performance of product codes is improved using iteration between outer and inner codes.Simulation results validate that BER of the product code with the proposed hybrid algorithm is lower than that of the product code with no erasure correction.Compared with other product codes using LDPC codes,the proposed LDPC-RS product code with the same code rate has much better performance and smaller rate loss attributed to the maximum distance separable(MDS)property and significant erasure-correction capability of RS codes. 展开更多
关键词 low-density parity-check codes product codes iterative decoding Reed-Solomon codes
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An Iterative Decoding Scheme for Davey-MacKay Construction 被引量:5
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作者 Yuan Liu Weigang Chen 《China Communications》 SCIE CSCD 2018年第6期187-195,共9页
In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the err... In the Davey-MacKay(DM) construction,the inner decoder treats unknown transmitted bits as random independent substitution errors. It limits the synchronization capability of the inner decoder, and thus weakens the error-correcting capability of the DM construction.In order to improve the performance of the DM construction, an iterative decoding scheme is proposed, which iteratively utilizes the more accurate estimates of transmitted codewords. In the proposed scheme, the estimated average bit error rates and the estimated low-density parity-check(LDPC) codewords from the outer decoder are fed back into the inner decoder to update the synchronization process. Simulation results show that the proposed iterative decoding scheme significantly outperforms the traditional DM construction. 展开更多
关键词 Davey-MacKay construction iterative decoding LDPC code synchronization error
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JOINT ITERATIVE DECODING FOR SIMPLE-ENCODING SYSTEMATIC IRREGULAR-LDPC-BASED CODED COOPERATION IN NON-IDEAL RELAY CHANNEL 被引量:3
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作者 Chen Jingwen Yang Fengfan +1 位作者 Luo Lin Tho Le-Ngoc 《Journal of Electronics(China)》 2010年第3期305-315,共11页
In this paper, a new kind of simple-encoding irregular systematic LDPC codes suitable for one-relay coded cooperation is designed, where the proposed joint iterative decoding is effectively performed in the destinatio... In this paper, a new kind of simple-encoding irregular systematic LDPC codes suitable for one-relay coded cooperation is designed, where the proposed joint iterative decoding is effectively performed in the destination which is in accordance with the corresponding joint Tanner graph characterizing two different component LDPC codes used by the source and relay in ideal and non-ideal relay cooperations. The theoretical analysis and simulations show that the coded cooperation scheme obviously outperforms the coded non-cooperation one under the same code rate and decoding complex. The significant performance improvement can be virtually credited to the additional mutual exchange of the extrinsic information resulted by the LDPC code employed by the source and its counterpart used by the relay in both ideal and non-ideal cooperations. 展开更多
关键词 Cooperative communication Low-density parity-check code Relay channel Joint Tanner graph Joint iterative decoding
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Accelerating BP-Based Iterative Low-Density Parity-Check Decoding by Modified Vertical and Horizontal Processes 被引量:2
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作者 陈婧文 仰枫帆 +1 位作者 罗琳 THO Le-Ngoc 《Journal of Southwest Jiaotong University(English Edition)》 2009年第4期275-282,共8页
Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity- check (LDPC) decoding over an additive white Gaussian noise (AWGN) channel, where th... Two modified BP algorithms related to vertical and horizontal processes are proposed to accelerate iterative low-density parity- check (LDPC) decoding over an additive white Gaussian noise (AWGN) channel, where the newly updated extrinsic information is immediately used in the current decoding round. Theoretical analysis and simulation results demonstrate that both the modified approaches provide significant performance improvements over the traditional BP algorithm with almost no additional decoding complexity. The proposed algorithm with modified horizontal process offers even better performance than another algorithm with the modified horizontal process. The two modified BP algorithms are very promising in practical communications since both can achieve an excellent trade-off between the performance and decoding complexity. 展开更多
关键词 LDPC codes iterative decoding BP algorithm Extrinsic information Horizontal process Vertical process
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Jointly-check iterative decoding algorithm for quantum sparse graph codes 被引量:1
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作者 邵军虎 白宝明 +1 位作者 林伟 周林 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期116-122,共7页
For quantum sparse graph codes with stabilizer formalism, the unavoidable girth-four cycles in their Tanner graphs greatly degrade the iterative decoding performance with standard belief-propagation (BP) algorithm. ... For quantum sparse graph codes with stabilizer formalism, the unavoidable girth-four cycles in their Tanner graphs greatly degrade the iterative decoding performance with standard belief-propagation (BP) algorithm. In this paper, we present a jointly-check iterative algorithm suitable for decoding quantum sparse graph codes efficiently. Numerical simulations show that this modified method outperforms standard BP algorithm with an obvious performance improvement. 展开更多
关键词 quantum error correction sparse graph code iterative decoding belief-propagation algorithm
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Iterative Decoding of Parallel Concatenated Block Codes and Coset Based MAP Decoding Algorithm for F24 Code 被引量:1
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作者 LI Ming, CAO Jia lin, DENG Jia mei School of Electromechanical Engineering and Automation, Shanghai University, Shanghai 200072, China 《Journal of Shanghai University(English Edition)》 CAS 2001年第2期116-122,共7页
A multi dimensional concatenation scheme for block codes is introduced, in which information symbols are interleaved and re encoded for more than once. It provides a convenient platform to design high performance co... A multi dimensional concatenation scheme for block codes is introduced, in which information symbols are interleaved and re encoded for more than once. It provides a convenient platform to design high performance codes with flexible interleaver size. Coset based MAP soft in/soft out decoding algorithms are presented for the F24 code. Simulation results show that the proposed coding scheme can achieve high coding gain with flexible interleaver length and very low decoding complexity. 展开更多
关键词 iterative decoding parallel concatenated codes MAP(maximum a posterior) decoding coset principle
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CHANNEL ESTIMATION FOR ITERATIVE DECODING OVER FADING CHANNELS 被引量:1
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作者 K.H.Sayhood 《Journal of Electronics(China)》 2002年第4期346-355,共10页
A method of coherent detection and channel estimation for punctured convolutional coded binary Quadrature Amplitude Modulation (QAM) signals transmitted over a frequency-flat Rayleigh fading channels used for a digita... A method of coherent detection and channel estimation for punctured convolutional coded binary Quadrature Amplitude Modulation (QAM) signals transmitted over a frequency-flat Rayleigh fading channels used for a digital radio broadcasting transmission is presented. Some known symbols are inserted in the encoded data stream to enhance the channel estimation process.The pilot symbols are used to replace the existing parity symbols so no bandwidth expansion is required. An iterative algorithm that uses decoding information as well as the information contained in the known symbols is used to improve the channel parameter estimate. The scheme complexity grows exponentially with the channel estimation filter length. The performance of the system is compared for a normalized fading rate with both perfect coherent detection (corresponding to a perfect knowledge of the fading process and noise variance) and differential detection of Differential Amplitude Phase Shift Keying (DAPSK). The tradeoff between simplicity of implementation and bit-error-rate performance of different techniques is also compared. 展开更多
关键词 CODES iterative decoding Channel estimation
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AMP Dual-Turbo Iterative Detection and Decoding for LDPC Coded Multibeam MSC Uplink 被引量:1
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作者 Yang Yang Wenjing Wang Xiqi Gao 《China Communications》 SCIE CSCD 2018年第6期178-186,共9页
The uplink of mobile satellite communication(MSC) system with hundreds of spot beams is essentially a multiple-input multiple-output(MIMO) channel. Dual-turbo iterative detection and decoding as a kind of MIMO receive... The uplink of mobile satellite communication(MSC) system with hundreds of spot beams is essentially a multiple-input multiple-output(MIMO) channel. Dual-turbo iterative detection and decoding as a kind of MIMO receiver, which exchanges soft extrinsic information between a soft-in soft-out(SISO) detector and an SISO decoder in an iterative fashion, is an efficient method to reduce the uplink inter-beam-interference(IBI),and so the receiving bit error rate(BER).We propose to replace the linear SISO detector of traditional dual-turbo iterative detection and decoding with the AMP detector for the low-density parity-check(LDPC) coded multibeam MSC uplink. This improvement can reduce the computational complexity and achieve much lower BER. 展开更多
关键词 multibeam mobile satellite communication approximate message passing turbo iterative detection and decoding
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Improved List Sphere Decoder for Multiple Antenna Systems 被引量:1
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作者 宫丰奎 葛建华 李兵兵 《Journal of Southwest Jiaotong University(English Edition)》 2008年第1期1-9,共9页
An improved list sphere decoder (ILSD) is proposed based on the conventional list sphere decoder (LSD) and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fix... An improved list sphere decoder (ILSD) is proposed based on the conventional list sphere decoder (LSD) and the reduced- complexity maximum likelihood sphere-decoding algorithm. Unlike the conventional LSD with fixed initial radius, the ILSD adopts an adaptive radius to accelerate the list cdnstruction. Characterized by low-complexity and radius-insensitivity, the proposed algorithm makes iterative joint detection and decoding more realizable in multiple-antenna systems. Simulation results show that computational savings of ILSD over LSD are more apparent with more transmit antennas or larger constellations, and with no performance degradation. Because the complexity of the ILSD algorithm almost keeps invariant with the increasing of initial radius, the BER performance can be improved by selecting a sufficiently large radius. 展开更多
关键词 iterative joint detection and decoding List sphere decoding (LSD) Maximum likelihood (ML) Soft in soft out (SISO) Multiple input multiple output (MIMO)
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Joint Iterative Decoding for Network-Coding-Based Multisource LDPC-Coded Cooperative MIMO
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作者 张顺外 仰枫帆 唐蕾 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2014年第4期420-430,共11页
A network-coding-based multisource LDPC-coded cooperative MIMO scheme is proposed,where multiple sources transmit their messages to the destination with the assistance from a single relay.The relay cooperates with mul... A network-coding-based multisource LDPC-coded cooperative MIMO scheme is proposed,where multiple sources transmit their messages to the destination with the assistance from a single relay.The relay cooperates with multiple sources simultaneously via network-coding.It avoids the issues of imperfect frequency/timing synchronization and large transmission delay which may be introduced by frequency-division multiple access(FDMA)/code-division multiple access(CDMA)and time-division multiple access(TDMA)manners.The proposed joint″Min-Sum″iterative decoding is effectively carried out in the destination.Such a decoding algorithm agrees with the introduced equivalent joint Tanner graph which can be used to fully characterize LDPC codes employed by the sources and relay.Theoretical analysis and numerical simulation show that the proposed scheme with joint iterative decoding can achieve significant cooperation diversity gain.Furthermore,for the relay,compared with the cascade scheme,the proposed scheme has much lower complexity of LDPC-encoding and is easier to be implemented in the hardware with similar bit error rate(BER)performance. 展开更多
关键词 cooperative MIMO network coding LDPC codes equivalent joint Tanner graph joint iterative decoding
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Iterative Demodulation and Decoding Scheme with 16 QAM
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作者 刘林南 匡镜明 +1 位作者 李鸣 费泽松 《Journal of Beijing Institute of Technology》 EI CAS 2006年第3期311-315,共5页
Iterative demodulation and decoding scheme is analyzed and modulation labeling is considered to be one of the crucial factors to this scheme. By analyzing the existent mapping design criterion, four aspects are found ... Iterative demodulation and decoding scheme is analyzed and modulation labeling is considered to be one of the crucial factors to this scheme. By analyzing the existent mapping design criterion, four aspects are found as the key techniques for choosing a label mapping. Based on this discovery, a novel mapping design criteflon is proposed and two label mappings are searched according to it. Simulation results show that the performance of BICM-ID using the novel mappings is better than the former ones. The extrinsic information transfer (EXIT) chart is introduced and it is used to evaluate the proposed mapping design criteria. 展开更多
关键词 bit-interleaved coded modulation with iterative decoding (BICM-ID) 16 quadrature amplitude modulation (16QAM) design criteria extrinsic information
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New Applications of EXIT Chart for Iterative Decoding Systems
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作者 宫丰奎 葛建华 李兵兵 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第1期35-39,共5页
Applications on iterative control and multiple input multiple output (MIMO) system were developed. Two new charts derived from extrinsic information transfer (EXIT) chart were employed as the designing tools, which ar... Applications on iterative control and multiple input multiple output (MIMO) system were developed. Two new charts derived from extrinsic information transfer (EXIT) chart were employed as the designing tools, which are called as output mutual information chart with defined iterative degree (DID) chart and near optimum output mutual information (NOMI) chart respectively. Different from the EXIT chart, they can show the iterative performance on the whole signal-to-noise ratio range with one single curve, whereas computation complexity is greatly reduced compared with conventional bit error ratio (BER) performance curve. The iterative control was implemented according to a near-optimum iterative degree vector determined by NOMI chart, the reasonability of uncertain parameters was analyzed in one MIMO system. The concepts were illustrated based on bit-interleaved coded modulation with iterative decoding (BICM-ID). 展开更多
关键词 extrinsic information transfer chart bit-interleaved coded modulation iterative decoding multiple input multiple output
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A NEW LABELING SEARCH ALGORITHM FOR BIT-INTERLEAVED CODED MODULATION WITH ITERATIVE DECODING
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作者 Zou Xuelan Feng Guangzeng 《Journal of Electronics(China)》 2008年第1期59-64,共6页
Bit-Interleaved Coded Modulation with Iterative Decoding (BICM-ID) is a bandwidth ef- ficient transmission, where the bit error rate is reduced through the iterative information exchange between the inner demapper and... Bit-Interleaved Coded Modulation with Iterative Decoding (BICM-ID) is a bandwidth ef- ficient transmission, where the bit error rate is reduced through the iterative information exchange between the inner demapper and the outer decoder. The choice of the symbol mapping is the crucial design parameter. This paper indicates that the Harmonic Mean of the Minimum Squared Euclidean (HMMSE) distance is the best criterion for the mapping design. Based on the design criterion of the HMMSE distance, a new search algorithm to find the optimized labeling maps for BICM-ID system is proposed. Numerical results and performance comparison show that the new labeling search method has a low complexity and outperforms other labeling schemes using other design criterion in BICM-ID system, therefore it is an optimized labeling method. 展开更多
关键词 Symbol labeling Bit-Interleaved Coded Modulation (BICM) iterative Decoding (ID) Harmonic Mean of the Minimum Squared Euclidean (HMMSE) distance
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Iterative Detection and Decoding Algorithm in Dual Polarized Land Mobile Satellite MIMO Systems
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作者 Yang Wang Dan-Feng Zhao Xi Liao 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第2期28-32,共5页
An iterative detection and decoding algorithm with outer code decision feedback is proposed for the dual polarized( DP) land mobile satellite( LMS) MIMO systems using concatenated codes. A feedback structure is added ... An iterative detection and decoding algorithm with outer code decision feedback is proposed for the dual polarized( DP) land mobile satellite( LMS) MIMO systems using concatenated codes. A feedback structure is added after the outer decoder in the proposed algorithm. The feedback information is exploited to control the detecting list in the MIMO detector and reduce the number of symbols which have to be processed at each iteration. As a result,the computational complexity is reduced. Meanwhile,the successfully decoded outer code words are used to calculate the more reliable initial information for the inner decoder and the system performance can be improved by this step. The simulation results show that the proposed algorithm can reduce the computational complexity compared to the traditional iterative detection and decoding algorithm and achieve better performance. 展开更多
关键词 satellite communications multiple-input multiple-output(MIMO) dual polarization iterative detection and decoding
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Design and Implementation of a Novel Algorithm for Iterative Decoding of Product Codes
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作者 李宗旺 Song +2 位作者 Wentao Luo Hanwen 《High Technology Letters》 EI CAS 2003年第1期35-40,共6页
A novel product code iterative decoding algorithm and its high speed implementation scheme are proposed in this paper. Based on partial combination of selected columns of check matrix, the reduced-complexity syndrome ... A novel product code iterative decoding algorithm and its high speed implementation scheme are proposed in this paper. Based on partial combination of selected columns of check matrix, the reduced-complexity syndrome decoding method is proposed to decode sub-codes of product code and deliver soft output information. So iterative decoding of product codes is possible. The fast sorting algorithm and a look-up method are proposed for high speed implementation of this algorithm. Compared to the conventional weighing iterative algorithm, the proposed algorithm has lower complexity while offering better performance, which is demonstrated by simulations and implementation analysis. The implementation scheme and verilog HDL simulation show that it is feasible to achieve high speed decoding with the proposed algorithm. 展开更多
关键词 iterative decoding product codes syndrome decoding FPGA
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Realtime robust speech communication based on iterative joint source-channel decoding and demodulation algorithm for MELP vocoder
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作者 彭坦 Cui Huijuan Tang Kun 《High Technology Letters》 EI CAS 2010年第2期111-116,共6页
Realtime speech communications require high efficient compression algorithms to encode speech signals. As the compressed speech parameters are highly sensitive to transmission errors, robust source and channel decodin... Realtime speech communications require high efficient compression algorithms to encode speech signals. As the compressed speech parameters are highly sensitive to transmission errors, robust source and channel decoding and demodulation schemes are both important and of practical use. In this paper, an it- erative joint souree-channel decoding and demodulation algorithm is proposed for mixed excited linear pre- diction (MELP) vocoder by both exploiting the residual redundancy and passing soft information through- out the receiver while introducing systematic global iteration process to further enhance the performance. Being fully compatible with existing transmitter structure, the proposed algorithm does not introduce addi- tional bandwidth expansion and transmission delay. Simulations show substantial error correcting perfor- mance and synthesized speech quality improvement over conventional separate designed systems in delay and bandwidth constraint channels by using the joint source-channel decoding and demodulation (JSCCM) algorithm. 展开更多
关键词 speech coding joint souree-channel coding and modulation (JSCCM) iterative decoding
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Convergence Analysis of Iterative Threshold Decoding Process
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作者 Mohammed Lahmer Mostafa Belkasmi Abdallah Rhattoy 《Journal of Computer and Communications》 2016年第14期98-107,共11页
Today the error correcting codes are present in all the telecom standards, in particular the low density parity check (LDPC) codes. The choice of a good code for a given network is essentially linked to the decoding p... Today the error correcting codes are present in all the telecom standards, in particular the low density parity check (LDPC) codes. The choice of a good code for a given network is essentially linked to the decoding performance obtained by the bit error rate (BER) curves. This approach requires a significant simulation time proportional to the length of the code, to overcome this problem Exit chart was introduced, as a fast technique to predict the performance of a particular class of codes called Turbo codes. In this paper, we success to apply Exit chart to analyze convergence behavior of iterative threshold decoding of one step majority logic decodable (OSMLD) codes. The iterative decoding process uses a soft-input soft-output threshold decoding algorithm as component decoder. Simulation results for iterative decoding of simple and concatenated codes transmitted over a Gaussian channel have shown that the thresholds obtained are a good indicator of the Bit Error Rate (BER) curves. 展开更多
关键词 OSMLD EXIT BER Mutual Information iterative Threshold Decoding Extrinsic Information LLR
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Construction of Protograph LDPC Codes Based on the Convolution Neural Network
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作者 Zhiyuan Xiao Liguang Li +1 位作者 Jin Xu Jin Sha 《China Communications》 SCIE CSCD 2023年第5期84-92,共9页
This paper presents an intelligent protograph construction algorithm.Protograph LDPC codes have shown excellent error correction performance and play an important role in wireless communications.Random search or manua... This paper presents an intelligent protograph construction algorithm.Protograph LDPC codes have shown excellent error correction performance and play an important role in wireless communications.Random search or manual construction are often used to obtain a good protograph,but the efficiency is not high enough and many experience and skills are needed.In this paper,a fast searching algorithm is proposed using the convolution neural network to predict the iterative decoding thresholds of protograph LDPC codes effectively.A special input data transformation rule is applied to provide stronger generalization ability.The proposed algorithm converges faster than other algorithms.The iterative decoding threshold of the constructed protograph surpasses greedy algorithm and random search by about 0.53 dB and 0.93 dB respectively under 100 times of density evolution.Simulation results show that quasi-cyclic LDPC(QC-LDPC)codes constructed from the proposed algorithm have competitive performance compared to other papers. 展开更多
关键词 LDPC codes protograph codes iterative decoding threshold neural network
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