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Description: LDPC研究者MacKay提供的校验矩阵H和对应的G，其中H的行重12，列重6，行数504，列数1008，任意两行不含围长为4的圈-LDPC researchers MacKay, the calibration matrix corresponding to the H and G, in which the re-H 12, series 6, a few 504, cited 1008, the two firms were non-arbitrary girth to the ring 4
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Author: 心海 |
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Description: LDPC是现在用的比较多的信道编码方式，该文章对LDPC编码进行了由潜入深的介绍-LDPC is now more of the channel coding, The article on LDPC coding by the introduction into the deep
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Author: dina |
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Description: LDPC中的效验矩阵里面有无4环对译码性能的影响，用MTLAB写的-LDPC matrix of well-tested inside the 4 ring on whether the impact of decoding performance, written by MTLAB
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Author: 钟声 |
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Description: Flexible construction of girth-six QC-LDPC Codes-The program constructs girth-six QC-LDPC codes given row-weight,k, column-weight,j, and sub-matrix size,m. The obtained parity-check matrix is stored in H. The construction has flexibility in that j,k and m can be varied.The program achieves girth-six by applying the row-column constraint. There are m rows in j submatrices. No two rows should share the same column more than once. This constraint is applied to avoid 4-cycles. The construction has flexibility in that j,k and m can be varied.
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Author: lydia |
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Description: Construct the short length of QC LDPC codes without girth 4 and girth 6-The Program to construct the short length of QC LDPC codes without girth 4 and girth 6
Copyright (C) Yang XIAO, Jun FAN, BJTU, July 26, 2007, E-Mail: yxiao@bjtu.edu.cn.
This program presents an approach [1] for constructing the short length of LDPC codes with girth 8. First, we design 3 submatrices with different shifting functions given by our schemes, then combine them into a matrix according to our approach, finally, expand the matrix into a desired parity-check matrix using identity matrices and cyclic shift matrices of the identity matrices.
The simulation results in AWGN channels show that the codes which can be obtained by the generator matrix derived from this check matrix for encoding the random information bits are as good as random LDPC codes [1].
Ref:
[1] J. Fan, Y. Xiao, “A design of LDPC codes with large girth based on the sub-matrix shifting”, IET International Conference on Wireless Mobile and Multimedia Networks Proceedings (ICWMMN 2006), (CP525), p.
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Author: lydia |
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Description: LDPC Coded Modulations, by Franceschini, Ferrari and Raheli,2009年Springer的新书。关于LDPC-LDPC Coded Modulations, by Franceschini, Ferrari and Raheli, new book in 2009, published by Springer, about LDPC coding, decoding.
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Author: 查哲 |
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Description: The paper is about bounds for LDPC and LDGM codes under MAP. A new method for analyzing low density parity check (LDPC) codes and low density generator
matrix (LDGM) codes under bit maximum a posteriori probability (MAP) decoding is
introduced. The method is based on a rigorous approach to spin glasses developed by Francesco
Guerra. It allows to construct lower bounds on the entropy of the transmitted message conditional
to the received one. Based on heuristic statistical mechanics calculations, we conjecture
such bounds to be tight. The result holds for standard irregular ensembles when used over
binary input output symmetric channels.
The method is first developed for Tanner graph ensembles with Poisson left degree distribution.
It is then generalized to ‘multi-Poisson’ graphs, and, by a completion procedure, to
arbitrary degree distribution.
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Author: mike zhou |
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Description: Low-density parity-check (LDPC) codes are a class of linear block LDPC
codes. The name comes from the characteristic of their parity-check
matrix which contains only a few 1’s in comparison to the amount of
0’s. Their main advantage is that they provide a performance which
is very close to the capacity for a lot of different channels and linear
time complex algorithms for decoding. Furthermore are they suited
for implementations that make heavy use of parallelism.
They were first introduced by Gallager in his PhD thesis in 1960. Gallager,
But due to the computational effort in implementing coder and en- 1960
coder for such codes and the introduction of Reed-Solomon codes,
they were mostly ignored until about ten years ago
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Author: mike zhou |
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Description: L D P C 码( 低密度校验码) 又称哥拉格( G a l l a g e r )， 它由G a l l a g e r 于1 9 6 2 年发明并研究。9年代后, L D P C码被S p i e l m a n 和M a c k a y 等人再度发现并发展， 从此信道编码领域出现了研究 L D P C码的热潮。-LDPC code (LDPC), also known as Ge Lage (G allager), which by the G allager in 1962 invented and studied. After 9 years, LDPC codes are S pielman and M ackay, who re-discovered and developed, from the field of channel coding to study wave of LDPC codes.
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Author: houfengzhi |
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Description: 低密度奇偶校验码(简称LDPC码)是目前距离香农限最近的一种线性纠错码，它的直接编码运算量较大，通常具有码长的二次方复杂度．为此，利用有效的校验矩阵，来降低编码的复杂度，同时研究利用大规模集成电路实现LDPC码的编码．在ISE 8．2软件平台上采用基于FPGA的Verilog HDL语言实现了有效的编码过程，为LDPC码的硬件实现和实际应用提供了依据-Abstract：Low．density parity·check code(LDPC code)is a kind of linear eror·correcting code nearest to Shannon Limit．For LDPC
cod e，the computational overhead for direct encoding operations is large，as the complexity of encod ing is the square of the length of
codeword．Hence，this paper reduces the complexity of coding by using effective parity—check matrix，and realizes the encoding device
for LDPC code by use of large·scale integrated circuits．The effective encoding process based on FPGA with Verilog HDL language is
implemented on ISE 8．2 software platform ，providing a feasible basis for hardware implementation an d practical application of LDPC
code．
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Author: 秦小星 |
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Description: 针对目前应用比较广泛的基于准循环矩阵构造的QC-LDPC(准循环LDPC)码的各种构造方法,分析比较了随机构造LDPC和各种准循环LDPC编码方法的优缺点,通过理论分析和MATLAB中的性能仿真,提出的相应的优化方案-Broader view of the present application of quasi-circulant matrices based QC-LDPC (quasi-cyclic LDPC) codes for the various construction methods, structural analysis and comparison of the random LDPC and various quasi-cyclic LDPC coding advantages and disadvantages, through theoretical analysis and MATLAB The performance simulation, optimization scheme proposed by the corresponding
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Author: qiaohui |
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Description: 用FPGA实现使用LDPC编码器和译码器-FPGA implementation by using LDPC encoder and decoder
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Size: 484352 |
Author: 雷锋 |
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Description: 中国数字调频广播技术方案CDRadio实现了真正的带内数模混叠同播，并通过使用非规则频谱分配、LDPC纠错编码、时间分片等关键技术，获得了更好的性能增益。-CDRadio supports the real in-band mixed broadcast of both digital and analog signals，and gains better
performance by adopting key technologies such as irregular spectrum allocation，
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Author: houjue |
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Description: Lowering LDPC Error Floors by Postprocessing
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Author: omrano.rs |
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Description: qc-ldpc码编程，围长为6，列重为3，无4环-The algorithm divides rows into three equal groups. The rows are then connnected to form a distance graph which is then transformed in to a matrix. Girth of six is maintained by avoiding four-cycles. No two rows are connected more than once (the row-column constraint).
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Author: ss |
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Description: This my research about Error fixing.
For low-end devices with limited battery or computational power, low complexity decoders
are beneficial. In this research we have searched for low complexity decoder alternatives for
error and error-erasure channels. We have especially focused on low complexity error erasure
decoders, which is a topic that has not been studied by many researchers.-This is my research about Error fixing.
For low-end devices with limited battery or computational power, low complexity decoders
are beneficial. In this research we have searched for low complexity decoder alternatives for
error and error-erasure channels. We have especially focused on low complexity error erasure
decoders, which is a topic that has not been studied by many researchers.
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Size: 798720 |
Author: aydim turkken |
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Description: 。并行级联LDPC码是由多个码率不同的子码，经并行级联后得到的码率可变的LDPC码。本文提出了基于
并行级联LDPC码的递增冗余HARQ方案，给出了这种方案的吞吐量性能封闭解。在AwGN信道和Rayleigh衰落信
道下，通过仿真将新方案的性能和随机LDPC码的性能进行了比较。结果显示，并行级联LDPC码的递增冗余HARQ
方案性能接近随机LDPc码，但编、译码更简单，参数选择范围更广。-. Parallel Concatenated LDPC code is different by a plurality of bit-rate sub-code, the LDPC code rate is variable obtained after parallel concatenation. In this paper, the incremental redundancy HARQ scheme based on parallel concatenated LDPC codes, the throughput performance of this program is given closed-form solution. In AwGN channel and Rayleigh fading channels through simulation, the performance of the performance of the new program and random LDPC codes are compared. The results show that the parallel concatenated LDPC codes incremental redundancy HARQ scheme performance close to the random LDPc code, but compiled more simple decoding a wider range of parameter selection.
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Author: 李腾飞 |
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Description: 对提高可见光通信传输速率的研究，并提出了使用LDPC编码来降低干扰。-In order to increase a transmission rate, the transmitter is
composed of plural LEDs and sends digital information by
independently controlling brightness of them, which is called
parallel transmissions. The receiver captures the state of the
LEDs by using an image sensor and restores the information by
image processing. In the parallel transmissions, since interference
between LEDs causes performance degradation, we introduce an
LDPC code to mitigate the influence of interference.
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Author: 易利 |
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Description: 本文给出Q 矩阵的定义, 在此基础上提出由Q 矩阵构造的LDPC 码新码族-In this paper, the definition of Q matrix Q matrix proposed by the new code of LDPC codes constructed on the basis of race
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Author: 李科 |
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Description: 一种新型的建筑不规则低密度
奇偶检验基于所述修改（LDPC）码
渐进边增长（PEG）的算法。边缘
所述PEG算法的位置是由利用所述Sum-增强
积算法在奇偶校验矩阵的设计。该
提出的算法是在块长度和速度非常灵活。
被提议的方法构建代码的测试
AWGN信道和显著的性能改进
实现。建议解码器优化的灵活性
动作，然后由它的使用在修改所述改进的示
PEGIPEGI）算法来实现进一步的性能提升。-A novel construction for irregular low-density
parity-check (LDPC) codes based on a modification of the
Progressive Edge Growth (PEG) algorithm is presented. Edge
placement of the PEG algorithm is enhanced by use of the Sum-
Product algorithm in the design of the parity-check matrix. The
proposed algorithm is highly flexible in block length and rate.
The codes constructed by the proposed methods are tested in the
AWGN channel and significant performance improvements are
achieved. The flexibility of the proposed decoder optimisation
operation is then shown by its use in modifying the Improved
PEG (IPEG) algorithm to achieve further performance gains.
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Author: 我问问 |
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