共查询到18条相似文献,搜索用时 187 毫秒
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相比于最小和译码算法,LDPC码的另外一种译码算法——比特翻转译码算法实现更简单,但其性能有较大恶化。最近提出的有噪梯度下降比特翻转译码(NGDBF)算法性能相比简单的比特翻转算法性能有明显提高,但该算法一次翻转一个比特限制了其应用。结合并行加权比特翻转译码(PWBF)中翻转标记的思想,本文提出了一种NGDBF译码的改进算法——并行NGDBF译码及其自适应形式,克服了PWBF译码对行重/列重较小的LDPC码性能不佳的缺陷。仿真表明:并行NGDBF译码的性能优于相应的NGDBF译码,其自适应形式不仅性能逼近最小和译码,而且实现简单。 相似文献
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LDPC码的硬判决译码通常是利用比特翻转算法(BF)以及在其基础上改进的加权比特翻转算法(WBF)来实现的,但是前者算法性能较差,而后者的复杂度较高,为了让译码算法能够兼顾其性能和复杂度,针对之前的BF以及WBF算法,提出了一种改进的LDPC码硬判决译码算法,该算法能够在前两次迭代中完成多个比特位的翻转.仿真结果表明,这种改进的算法可以在性能损失较小的条件下,大大降低算法的复杂度,从而提高译码的效率,减轻硬件的负担. 相似文献
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针对现有的密钥生成方案需要在通信流程中增加额外的密钥协商协议,导致在5G等标准通信系统中应用受限的问题,该文提出一种基于极化码的无协商密钥物理层安全传输方案。首先基于信道特征提取未协商的物理层密钥,然后针对物理信道与密钥加密信道共同构成的等效信道设计极化码,最后利用未协商的物理层密钥对编码后的序列进行简单的模二加加密后传输。该方案通过针对性设计的极化码纠正密钥差异和噪声引起的比特错误,实现可靠的安全传输。仿真表明,该文基于等效信道设计的极化码在保证合法双方以最优的码率可靠传输的同时可以防止窃听者窃听,实现了安全与通信的一体化。 相似文献
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针对低密度奇偶校验(LDPC)码中加权比特翻转(WBF)译码算法在迭代过程中绝大多数情况都是进行单比特翻转,导致译码效率低并且可能会发生比特翻转"死循环"的现象,提出一种更为高效的加权比特翻转(EWBF)算法.该算法对翻转阈值进行了改进,使得每次迭代能够翻转多个比特,提高译码效率,并且能够避免译码过程出现的翻转"死循环"现象.仿真结果表明,所提译码算法与WBF算法、改进的WBF(MWBF)算法和IMWBF(Improved MWBF)算法相比,平均迭代次数分别降低51.6%~56.2%、49.6%~54.2%和48.1%~51.3%;而在译码性能方面,算法性能接近甚至优于IMWBF算法,当最大迭代次数设定为30次时,相比于IMWBF算法,在误码率为10-4时可获得0.92 dB的增益. 相似文献
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仿真结果表明,对于列重和行重较小的低密度奇偶校验(Low Density Parity-check,LDPC)码而言,梯度下降比特翻转(Gradient Descent Bit-flipping,GDBF)译码算法展现出巨大的性能优势,但其对于基于有限域几何构造的列重和行重较大的LDPC码则性能损失严重.该文首先分析指出,对于大列重LDPC码而言,翻转函数中的“互相关项”和“双极性校验子求和项”之间的“不匹配”是造成性能损失的主要原因.其次,引入一种可靠性度量对双极性校验子进行加权,上述“不匹配”现象得到有效削弱,从而改善GDBF算法对大列重LDPC码的译码性能.仿真结果表明,在加性高斯白噪声信道下,相比于传统的GDBF算法,新提出的算法在误比特率为10-5时可获得0.8 dB的增益. 相似文献
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Parallel Weighted Bit-Flipping Decoding 总被引:1,自引:0,他引:1
Xiaofu Wu Chunming Zhao Xiaohu You 《Communications Letters, IEEE》2007,11(8):671-673
A parallel weighted bit-flipping (PWBF) decoding algorithm for low-density parity-check (LDPC) codes is proposed. Compared to the best known serial weighted bit-flipping decoding, the PWBF decoding converges significantly faster but with little performance penalty. For decoding of finite-geometry LDPC codes, we demonstrate through examples that the proposed PWBF decoding converges in about 5 iterations with performance very close to that of the standard belief-propagation decoding. 相似文献
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LDPC码加权位翻转解码算法的研究 总被引:1,自引:1,他引:0
本文以Tanner图上的迭代消息流传递技术为基础,分析了Gallager提出的LDPC码第一解码方案,给出基于校验和的位翻转硬判决解码算法。在此基础上引入接收信号作为可靠性评估,使评估值作为硬判决的加权系数,从而提出基于校验和的加权位翻转解码算法。加权位翻转算法充分考虑了接收符号的信息;为了快速搜索翻转位,对不满足的校验方程数采用最大投票数排队算法。这些措施的合理应用改善了基于校验和的位翻转解码算法的性能。 相似文献
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OFDM是一项能有效对抗高速无线通信中多径衰落的关键技术,为了进一步提高OFDM系统的误码性能,许多信道编码技术已被应用于OFDM系统中,二元域LDPC码以其近香农限的误码性能和较低的译码复杂度成为研究的热点。在AWGN信道下,多元域LDPC码比等效码长的二元域LDPC码有更好的纠错性能。本文提出了一种将多元域LDPC码经过MPSK调制后用于OFDM系统的新方法。仿真结果表明,在多径衰落信道下,通过合理选择多元LDPC码域的阶数和调制的方法,多元域LDPC编码的高阶调制OFDM系统比等效码长的二元域LDPC编码OFDM系统具有更好的性能,并且由于采用了多元域LDPC的快速BP译码,译码复杂度只是稍有增加。 相似文献
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The simplicity of decoding is one of the most important characteristics of the low density parity check (LDPC) codes. Belief propagation (BP) decoding algorithm is a well‐known decoding algorithm for LDPC codes. Most LDPC codes with long lengths have short cycles in their Tanner graphs, which reduce the performance of the BP algorithm. In this paper, we present 2 methods to improve the BP decoding algorithm for LDPC codes. In these methods, the calculation of the variable nodes is controlled by using “multiplicative correction factor” and “additive correction factor.” These factors are obtained for 2 separate channels, namely additive white Gaussian noise (AWGN) and binary symmetric channel (BSC), as 2 functions of code and channel parameters. Moreover, we use the BP‐based method in the calculation of the check nodes, which reduces the required resources. Simulation results show the proposed algorithm has better performance and lower decoding error as compared to BP and similar methods like normalized‐BP and offset‐BP algorithms. 相似文献
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An initial bootstrap step for the decoding of low-density parity-check (LDPC) codes is proposed. Decoding is initiated by first erasing a number of less reliable bits. New values and reliabilities are then assigned to erasure bits by passing messages from nonerasure bits through the reliable check equations. The bootstrap step is applied to the weighted bit-flipping algorithm to decode a number of LDPC codes. Large improvements in both performance and complexity are observed. 相似文献
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In short-range wireless communication system(SWCS),the complex scenarios make its transmission face the diverse interference,and lower hardware resource leads to its limited anti-interference capability.To achieve the reliable transmission,a frequency-hopping-based SWCS (FH-SWCS)with improved LDPC (I-LDPC) code was constructed.In FH-SWCS,a low-complexity check-sum updating(LCU)algorithm was proposed to reduce the amount of computation.LCU-based multi-threshold bit flipping (LCU-MTBF) algorithm was given to increase the reliability of bit-flipping, improving decoding performance and reduce the complexity of decoding.The simulation results demonstrate that LCU is suitable for multiple hard decisions decoding algorithm,and it can reduce the computational complexity of original decoding algorithm without affecting its performance.When BER is 10?5,and iterations number is 5,0.15dB performance gain can be achieved,and the number of additions algorithm can be reduced about 40% in LCU-MTBF.In FH-SWCS with I-LDPC,when BER is 10?4,and SNR is 15dB,the performance gain about 7dB can be achieved to improve the anti-interference of the system effectively. 相似文献
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改进的离散字母表迭代译码算法研究 总被引:1,自引:0,他引:1
为了优化LDPC迭代译码性能和降低算法复杂度,提出了一种改进的基于Gallager A算法的2b离散字母表迭代译码算法。在每一轮迭代中,Tanner图上的校验节点与变量节点之间所传递的消息有1b表示符号值,另1b反映码字结构特性,其中变量节点更新规则是通过查表法来实现的。在二元对称信道下针对列重为3的规则LDPC码做了仿真实验,仿真结果表明该算法性能明显优于原算法,并且具有较低的复杂度。 相似文献