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DESIGN OF LOW-DENSITY PARITY CHECK CODES FOR MIMO SYSTEMS WITH DOUBLY-ITERATIVE RECEIVERS
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作者 Mei Zhonghui Li Xiaofei 《Journal of Electronics(China)》 2010年第4期553-556,共4页
In this paper, the Multiple Input Multiple Output (MIMO) doubly-iterative receiver which consists of the Probabilistic Data Association detector (PDA) and Low-Density Parity-Check Code (LDPC) decoder is developed. The... In this paper, the Multiple Input Multiple Output (MIMO) doubly-iterative receiver which consists of the Probabilistic Data Association detector (PDA) and Low-Density Parity-Check Code (LDPC) decoder is developed. The receiver performs two iterative decoding loops. In the outer loop, the soft information is exchanged between the PDA detector and the LDPC decoder. In the inner loop, it is exchanged between variable node and check node decoders inside the LDPC decoder. On the light of the Extrinsic Information Transfer (EXIT) chart technique, an LDPC code degree profile optimization algorithm is developed for the doubly-iterative receiver. Simulation results show the doubly-receiver with optimized irregular LDPC code can have a better performance than the one with the regular one. 展开更多
关键词 Probabilistic Data Association (PDA) Multiple-Input Multiple-Output (MIMO) low-density parity-check code (LDPC) Extrinsic Information Transfer (EXIT) chart
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Low-Complexity Optimization Algorithm for Irregular Low-Density Parity-Check Codes
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作者 左健存 邵宇丰 桂林 《Journal of Donghua University(English Edition)》 EI CAS 2013年第4期330-335,共6页
A low-complexity algorithm is proposed in this paper in order to optimize irregular low-density parity-check (LDPC) codes.The algorithm proposed can calculate the noise threshold by means of a one-dimensional densit... A low-complexity algorithm is proposed in this paper in order to optimize irregular low-density parity-check (LDPC) codes.The algorithm proposed can calculate the noise threshold by means of a one-dimensional density evolution and search the optimal degree profiles with fast-convergence differential evolution,so that it has a lower complexity and a faster convergence speed.Simulation resuits show that the irregular LDPC codes optimized by the presented algorithm can also perform better than Turbo codes at moderate block length even with less computation cost. 展开更多
关键词 irregular low-density parity-check (LDPC) codes Turbo codes optimizationCLC number:TN911.22Document code:AArticle ID:1672-5220(2013)04-0330-06
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Low-Density Parity-Check Codes: Research Status and Development Direction
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作者 Jie Xu Zhiyong Zheng Kun Tian 《Journal of Information Security》 2022年第4期257-271,共15页
In this paper, we conclude five kinds of methods for construction of the regular low-density parity matrix H and three kinds of methods for the construction of irregular low-density parity-check matrix H. Through the ... In this paper, we conclude five kinds of methods for construction of the regular low-density parity matrix H and three kinds of methods for the construction of irregular low-density parity-check matrix H. Through the analysis of the code rate and parameters of these eight kinds of structures, we find that the construction of low-density parity-check matrix tends to be more flexible and the parameter variability is enhanced. We propose that the current development cost should be lower with the progress of electronic technology and we need research on more practical Low-Density Parity-Check Codes (LDPC). Combined with the application of the quantum distribution key, we urgently need to explore the research direction of relevant theories and technologies of LDPC codes in other fields of quantum information in the future. 展开更多
关键词 low-density parity-check (LDPC) parity check Matrix H Quasi-Cyclic (QC) LDPC Spatially Coupled low-density parity-check (SC-LDPC) codes
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Application of the Henon Chaotic Model on to the Design of Low Density Parity Check Codes
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作者 XIAO Dongliang LIN Chunlei +1 位作者 SHI Hongling JIAO Bingli 《Wuhan University Journal of Natural Sciences》 CAS 2007年第3期485-490,共6页
A new method to design parity-check matrix based on Henon chaos model is presented. The designed parity-check matrix is with rather random behavior. Simulation results show that the proposed method makes an improvemen... A new method to design parity-check matrix based on Henon chaos model is presented. The designed parity-check matrix is with rather random behavior. Simulation results show that the proposed method makes an improvement in bit error rate (BER) performance by 0.4 dB compared with that of Luby for AWGN channel. The proposed method decreases the complexity of decoding significantly, and improves the error correcting performance of LDPC codes. It has been shown that Henon chaotic model is a powerful tool for construction of good LDPC codes, which make it possible to apply the LDPC code in real communication systems. 展开更多
关键词 LDPC codes CHAOS parity-check matrix Henon map
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JOINT SOURCE-CHANNEL DECODING OF HUFFMAN CODES WITH LDPC CODES 被引量:1
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作者 Mei Zhonghui Wu Lenan 《Journal of Electronics(China)》 2006年第6期806-809,共4页
In this paper, we present a Joint Source-Channel Decoding algorithm (JSCD) for Low-Density Parity Check (LDPC) codes by modifying the Sum-Product Algorithm (SPA) to account for the source redun-dancy, which results fr... In this paper, we present a Joint Source-Channel Decoding algorithm (JSCD) for Low-Density Parity Check (LDPC) codes by modifying the Sum-Product Algorithm (SPA) to account for the source redun-dancy, which results from the neighbouring Huffman coded bits. Simulations demonstrate that in the presence of source redundancy, the proposed algorithm gives better performance than the Separate Source and Channel Decoding algorithm (SSCD). 展开更多
关键词 low-density parity check codes (LDPC) Variable Length codes (VLC) Huffman code Sum-Product Algorithm(SPA) Joint Source-Channel Decoding (JSCD)
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Construction of protograph LDPC codes with circular generator matrices 被引量:5
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作者 Kaiyao Wang Yang Xiao Kiseon Kim 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第5期840-847,共8页
The application of protograph low density parity check (LDPC) codes involves the encoding complexity problem. Since the generator matrices are dense, and if the positions of "1" s are irregularity, the encoder nee... The application of protograph low density parity check (LDPC) codes involves the encoding complexity problem. Since the generator matrices are dense, and if the positions of "1" s are irregularity, the encoder needs to store every "1" of the generator matrices by using huge chip area. In order to solve this problem, we need to design the protograph LDPC codes with circular generator matrices. A theorem concerning the circulating property of generator matrices of nonsingular protograph LDPC codes is proposed. The circulating property of generator matrix of nonsingular protograph LDPC codes can be obtained from the corresponding quasi-cyclic parity check matrix. This paper gives a scheme of constructing protograph LDPC codes with circulating generator matrices, and it reveals that the fast encoding algorithm of protograph LDPC codes has lower encoding complexity under the condition of the proposed theorem. Simulation results in ad- ditive white Gaussian noise (AWGN) channels show that the bit error rate (BER) performance of the designed codes based on the proposed theorem is much better than that of GB20600 LDPC codes and Tanner LDPC codes. 展开更多
关键词 protograph low density parity check (LDPC) codes cyclic matrices fast encoding algorithm bit error rate (BER) performance.
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Construction of time-frequency codes based on protograph LDPC codes in OFDM communication systems 被引量:2
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作者 Kaiyao Wang Yang Xiao Kiseon Kim 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2012年第3期335-341,共7页
This paper proposes a scheme to construct time- frequency codes based on protograph low density parity check (LDPC) codes in orthogonal frequency division multiplexing (OFDM) communication systems. This approach s... This paper proposes a scheme to construct time- frequency codes based on protograph low density parity check (LDPC) codes in orthogonal frequency division multiplexing (OFDM) communication systems. This approach synthesizes two techniques: protograph LDPC codes and OFDM. One symbol of encoded information by protograph LDPC codes corresponds to one sub-carrier, namely the length of encoded information equals to the number of sub-carriers. The design of good protograph LDPC codes with short lengths is given, and the proposed proto- graph LDPC codes can be of fast encoding, which can reduce the encoding complexity and simplify encoder hardware implementa- tion. The proposed approach provides a higher coding gain in the Rayleigh fading channel. The simulation results in the Rayleigh fading channel show that the bit error rate (BER) performance of the proposed time-frequency codes is as good as random LDPC- OFDM codes and is better than Tanner LDPC-OFDM codes under the condition of different fading coefficients. 展开更多
关键词 time-frequency code protograph low density parity check (LDPC) code orthogonal frequency division multiplexing (OFDM) fast encoding algorithm.
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Performance analysis of LDPC codes on OOK terahertz wireless channels 被引量:1
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作者 刘纯 王长 曹俊诚 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第2期553-557,共5页
Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz(THz) wireless communications. An error control coding scheme based on low density parit... Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz(THz) wireless communications. An error control coding scheme based on low density parity check(LDPC) codes with soft decision decoding algorithm is proposed to improve the bit-error-rate(BER) performance of an on-off keying(OOK) modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications. 展开更多
关键词 terahertz wireless channels low density parity check codes atmospheric turbulence gamma-gamma models
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Quaternion Integers Based Higher Length Cyclic Codes and Their Decoding Algorithm 被引量:1
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作者 Muhammad Sajjad Tariq Shah +2 位作者 Mohammad Mazyad Hazzazi Adel R.Alharbi Iqtadar Hussain 《Computers, Materials & Continua》 SCIE EI 2022年第10期1177-1194,共18页
The decoding algorithm for the correction of errors of arbitrary Mannheim weight has discussed for Lattice constellations and codes from quadratic number fields.Following these lines,the decoding algorithms for the co... The decoding algorithm for the correction of errors of arbitrary Mannheim weight has discussed for Lattice constellations and codes from quadratic number fields.Following these lines,the decoding algorithms for the correction of errors of n=p−12 length cyclic codes(C)over quaternion integers of Quaternion Mannheim(QM)weight one up to two coordinates have considered.In continuation,the case of cyclic codes of lengths n=p−12 and 2n−1=p−2 has studied to improve the error correction efficiency.In this study,we present the decoding of cyclic codes of length n=ϕ(p)=p−1 and length 2n−1=2ϕ(p)−1=2p−3(where p is prime integer andϕis Euler phi function)over Hamilton Quaternion integers of Quaternion Mannheim weight for the correction of errors.Furthermore,the error correction capability and code rate tradeoff of these codes are also discussed.Thus,an increase in the length of the cyclic code is achieved along with its better code rate and an adequate error correction capability. 展开更多
关键词 Mannheim distance monoid ring cyclic codes parity check matrix extension syndromes decoding code rate and error correction capability
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High Robust Broadcasting over DTMB-A with Low-rate LDPC Codes 被引量:2
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作者 Chao Zhang Kewu Peng +2 位作者 Zhitong He Yonglin Xue Hui Yang 《China Communications》 SCIE CSCD 2022年第3期192-201,共10页
As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliabilit... As the 2nd generation digital terrestrial television broadcasting(DTTB)standard,digital terrestrial/television multimedia broadcasting-advanced(DTMB-A)can provide higher spectrum efficiency and transmission reliability by adopting flexible frame structure and advanced forward error correction coding compared with the 1 st generation DTTB systems.In order to increase the flexibility and robustness of the DTTB network,the frequency reuse scheme of factor one(reuse-1)is proposed,where the same RF channel is used by different stations covering the adjacent service areas.However,it demands a very low carrier-tonoise ratio(C/N)threshold below 0 dB at the DTTB physical layer.In this paper,a robust broadcasting technique is proposed based on DTMB-A with newly designed low-rate low density parity check(LDPC)codes.By adopting quasi-cyclic(QC)Raptor-like structure and progressive lifting method,the high performance low-rate LDPC codes are designed supporting multiple code lengths.Both density-evolution analyses and laboratory measurements demonstrate that DTMB-A with low-rate coding can complete the demodulation reliably with the C/N threshold below0 d B,which is one important necessary condition to support frequency reuse-1 scheme. 展开更多
关键词 digital terrestrial/television multimedia broadcasting-advanced(DTMB-A) digital terrestrial television broadcasting(DTTB) low-rate low density parity check(LDPC)code
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Design of good QC-LDPC codes without small girth in the p-plane 被引量:4
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作者 Lingjun Kong Yang Xiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第2期183-187,共5页
A construction method based on the p-plane to design high-girth quasi-cyclic low-density parity-check (QC-LDPC) codes is proposed. Firstly the good points in every line of the p-plane can be ascertained through filt... A construction method based on the p-plane to design high-girth quasi-cyclic low-density parity-check (QC-LDPC) codes is proposed. Firstly the good points in every line of the p-plane can be ascertained through filtering the bad points, because the designed parity-check matrixes using these points have the short cycles in Tanner graph of codes. Then one of the best points from the residual good points of every line in the p-plane will be found, respectively. The optimal point is also singled out according to the bit error rate (BER) performance of the QC-LDPC codes at last. Explicit necessary and sufficient conditions for the QC-LDPC codes to have no short cycles are presented which are in favor of removing the bad points in the p-plane. Since preventing the short cycles also prevents the small stopping sets, the proposed construction method also leads to QC-LDPC codes with a higher stopping distance. 展开更多
关键词 quasi-cyclic low-density parity-check (QC-LDPC)codes circulant matrices GIRTH stopping set stopping distance.
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DESIGN OF QUASI-CYCLIC LDPC CODES BASED ON EUCLIDEAN GEOMETRIES 被引量:4
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作者 Liu Yuanhua Niu Xinliang +1 位作者 Wang Xinmei Fan Jiulun 《Journal of Electronics(China)》 2010年第3期340-344,共5页
A new method for constructing Quasi-Cyclic (QC) Low-Density Parity-Check (LDPC) codes based on Euclidean Geometry (EG) is presented. The proposed method results in a class of QC-LDPC codes with girth of at least 6 and... A new method for constructing Quasi-Cyclic (QC) Low-Density Parity-Check (LDPC) codes based on Euclidean Geometry (EG) is presented. The proposed method results in a class of QC-LDPC codes with girth of at least 6 and the designed codes perform very close to the Shannon limit with iterative decoding. Simulations show that the designed QC-LDPC codes have almost the same performance with the existing EG-LDPC codes. 展开更多
关键词 low-density parity-check codes (LDPC) Quasi-Cyclic (QC) Euclidean Geometry (EG) Iterative method
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Weighted symbol-flipping decoding algorithm for nonbinary LDPC codes with flipping patterns 被引量:2
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作者 Bing Liu Jun Gao +1 位作者 Wei Tao Gaoqi Dou 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第5期848-855,共8页
A novel low-complexity weighted symbol-flipping algorithm with flipping patterns to decode nonbinary low-density parity-check codes is proposed. The proposed decoding procedure updates the hard-decision received symbo... A novel low-complexity weighted symbol-flipping algorithm with flipping patterns to decode nonbinary low-density parity-check codes is proposed. The proposed decoding procedure updates the hard-decision received symbol vector iteratively in search of a valid codeword in the symbol vector space. Only one symbol is flipped in each iteration, and symbol flipping function, which is employed as the symbol flipping metric, combines the number of failed checks and the reliabilities of the received bits and calculated symbols. A scheme to avoid infinite loops and select one symbol to flip in high order Galois field search is also proposed. The design of flipping pattern's order and depth, which is dependent of the computational requirement and error performance, is also proposed and exemplified. Simulation results show that the algorithm achieves an appealing tradeoff between performance and computational requirement over relatively low Galois field for short to medium code length. 展开更多
关键词 nonbinary low-density parity-check (LDPC) codes quasi-cyclic symbol-flipping (SF) decoding.
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Minimum distances of three families of low-density parity-check codes based on finite geometries 被引量:1
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作者 Yanan FENG Shuo DENG +1 位作者 Lu WANG Changli MA 《Frontiers of Mathematics in China》 SCIE CSCD 2016年第2期279-289,共11页
Three families of low-density parity-check (LDPC) codes are constructed based on the totally isotropic subspaces of symplectic, unitary, and orthogonal spaces over finite fields, respectively. The minimum distances ... Three families of low-density parity-check (LDPC) codes are constructed based on the totally isotropic subspaces of symplectic, unitary, and orthogonal spaces over finite fields, respectively. The minimum distances of the three families of LDPC codes in some special cases are settled. 展开更多
关键词 low-density parity-check (LDPC) code minimum distance symplectic UNITARY ORTHOGONAL
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Irregular and regular LDPC codes with high spectrum efficiency modulation in image transmission over fading channel 被引量:1
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作者 MaPiming YuanDongfeng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2005年第1期26-30,共5页
If the degree distribution is chosen carefully, the irregular low-density parity-check (LDPC) codes can outperform the regular ones. An image transmission system is proposed by combining regular and irregular LDPC cod... If the degree distribution is chosen carefully, the irregular low-density parity-check (LDPC) codes can outperform the regular ones. An image transmission system is proposed by combining regular and irregular LDPC codes with 16QAM/64QAM modulation to improve both efficiency and reliability. Simulaton results show that LDPC codes are good coding schemes over fading channel in image communication with lower system complexity. More over, irregular codes can obtain a code gain of about 0.7 dB compared with regular ones when BER is 10 -4. So the irregular LDPC codes are more suitable for image transmission than the regular codes. 展开更多
关键词 irregular low-density parity-check (LDPC) codes degree distribution image transmission high spectrum efficiency modulation.
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Construction of Rate-Compatible(RC) Low-Density Parity-Check(LDPC) Convolutional Codes Based on RC-LDPC Block Codes 被引量:1
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作者 穆丽伟 韩国军 刘志勇 《Journal of Shanghai Jiaotong university(Science)》 EI 2016年第6期679-683,共5页
In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are de... In this paper,a family of rate-compatible(RC) low-density parity-check(LDPC) convolutional codes can be obtained from RC-LDPC block codes by graph extension method.The resulted RC-LDPC convolutional codes,which are derived by permuting the matrices of the corresponding RC-LDPC block codes,are systematic and have maximum encoding memory.Simulation results show that the proposed RC-LDPC convolutional codes with belief propagation(BP) decoding collectively offer a steady improvement on performance compared with the block counterparts over the binary-input additive white Gaussian noise channels(BI-AWGNCs). 展开更多
关键词 rate-compatible(RC) low-density parity-check(LDPC) convolutional codes systematic maximum encoding memory belief propagation(BP) decoding
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Construction of Regular Rate-Compatible LDPC Convolutional Codes 被引量:1
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作者 Liwei Mu Chulong Liang +1 位作者 Zhiyong Liu Daru Pan 《China Communications》 SCIE CSCD 2016年第8期97-102,共6页
In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended... In this paper, we propose a new method to derive a family of regular rate-compatible low-density parity-check(RC-LDPC) convolutional codes from RC-LDPC block codes. In the RC-LDPC convolutional family, each extended sub-matrix of each extended code is obtained by choosing specified elements from two fixed matrices HE1K and HE1K, which are derived by modifying the extended matrices HE1 and HE2 of a systematic RC-LDPC block code. The proposed method which is based on graph extension simplifies the design, and prevent the defects caused by the puncturing method. It can be used to generate both regular and irregular RC-LDPC convolutional codes. All resulted codes in the family are systematic which simplify the encoder structure and have maximum encoding memories which ensure the property. Simulation results show the family collectively offer a steady improvement in performance with code compatibility over binary-input additive white Gaussian noise channel(BI-AWGNC). 展开更多
关键词 binary-input additive white Gaussian noise channel(BI-AWGNC) extended matrices rate-compatible low-density parity-check(RC-LDPC) convolutional codes
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A NOVEL CONSTRUCTION OF QUANTUM LDPC CODES BASED ON CYCLIC CLASSES OF LINES IN EUCLIDEAN GEOMETRIES
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作者 CaoDong SongYaoliang ZhaoShengmei 《Journal of Electronics(China)》 2012年第1期1-8,共8页
The dual-containing (or self-orthogonal) formalism of Calderbank-Shor-Steane (CSS) codes provides a universal connection between a classical linear code and a Quantum Error-Correcting Code (QECC). We propose a novel c... The dual-containing (or self-orthogonal) formalism of Calderbank-Shor-Steane (CSS) codes provides a universal connection between a classical linear code and a Quantum Error-Correcting Code (QECC). We propose a novel class of quantum Low Density Parity Check (LDPC) codes constructed from cyclic classes of lines in Euclidean Geometry (EG). The corresponding constructed parity check matrix has quasi-cyclic structure that can be encoded flexibility, and satisfies the requirement of dual-containing quantum code. Taking the advantage of quasi-cyclic structure, we use a structured approach to construct Generalized Parity Check Matrix (GPCM). This new class of quantum codes has higher code rate, more sparse check matrix, and exactly one four-cycle in each pair of two rows. Ex-perimental results show that the proposed quantum codes, such as EG(2,q)II-QECC, EG(3,q)II-QECC, have better performance than that of other methods based on EG, over the depolarizing channel and decoded with iterative decoding based on the sum-product decoding algorithm. 展开更多
关键词 Quantum Error-Correcting codes (QECC) Low Density parity check (LDPC) codes Finite geometry Euclidean Geometry (EG) Stabilizer codes Quasi-cyclic codes
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Efficient Early Termination Strategy for LDPC Codes in GPS Systems
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作者 Feng Wang Jin-Hai Li +1 位作者 Jin-Hai Sun Yue-Peng Yan 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2013年第6期118-122,共5页
By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is b... By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes. 展开更多
关键词 GPS system low-density parity-check (LDPC) codes early termination (ET) strategy cyclic redundancy check (CRC)CLC number:TN911.22 Document code:AArticle ID:1005-9113(2013)06-0118-05
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Multistep Linear Programming Approaches for Decoding Low-Density Parity-Check Codes
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作者 刘海洋 马连荣 陈杰 《Tsinghua Science and Technology》 SCIE EI CAS 2009年第5期556-560,共5页
The problem of improving the performance of linear programming(LP) decoding of low-density parity-check(LDPC) codes is considered in this paper.A multistep linear programming(MLP) algorithm was developed for dec... The problem of improving the performance of linear programming(LP) decoding of low-density parity-check(LDPC) codes is considered in this paper.A multistep linear programming(MLP) algorithm was developed for decoding LDPC codes that includes a slight increase in computational complexity.The MLP decoder adaptively adds new constraints which are compatible with a selected check node to refine the results when an error is reported by the original LP decoder.The MLP decoder result is shown to have the maximum-likelihood(ML) certificate property.Simulations with moderate block length LDPC codes suggest that the MLP decoder gives better performance than both the original LP decoder and the conventional sum-product(SP) decoder. 展开更多
关键词 low-density parity-check(LDPC) codes linear programming(LP) LP decoding pseudocode-word maximum-likelihood(ML) certificate property
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