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为了在译码性能和复杂度之间取得折中,针对低密度奇偶校验(Low Density Parity Check,LDPC)短码设计了加权比特翻转(Weighted Bit-Flipping,WBF)译码与顺序统计量译码(Ordered Statistics Decoding,OSD)的组合译码方法。在接收端,首先进行WBF译码,如果译码失败,则将原始接收序列送入OSD进行译码,最后输出OSD译码结果,这种组合方式称为WBF-OSD-I译码。为了进一步提高译码性能,考虑到WBF-OSD-I译码算法中WBF译码存在的不可检错误导致译码错误的接收序列并没有进入OSD译码器进行译码,设计了WBF-OSD-II组合译码方式。这种WBF-OSD-II组合译码方式通过比较WBF译出的估计码字与接收序列的距离,根据选择的门限决定是否使用OSD译码,从而进一步降低译码错误概率。仿真分析验证了LDPC短码的WBF-OSD组合译码性能。 相似文献
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针对Viterbi译码算法的计算复杂度随着卷积码约束长度的增加呈指数增加,译码延迟过大,只适用于约束长度较小的卷积码译码的缺陷,提出了适用于大约束度的卷积码译码方法.采用了改进粒子群优化算法,弥补传统粒子群优化算法在解决离散问题方面的缺陷--对卷积码快速译码.该方法通过设定种群规模M来确定译码路径数,极大地缩小了译码网格中的路径搜索范围,使译码延迟减小,更适用于约束长度较大的卷积码.还提出了译码宽度自适应的卷积码译码方法,对Viterbi译码算法进行了改进,把固定的译码路径宽度改进为随信道噪声的变化而变化,大大降低译码计算复杂度.仿真实验表明提出的2种译码方法的有效性. 相似文献
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Turbo乘积码仿真研究 总被引:2,自引:1,他引:1
Turbo codes译码算法的核心是软输入/软输出迭代译码,把这种思想应用于乘积码的译码中,得到了Turbo乘积码(TPC)迭代译码算法。介绍了基于扩展汉明码的乘积码的迭代译码算法,时该算法在AWGN信道中的译码性能进行了仿真。 相似文献
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基于遗传算法与Chase译码算法的各自优势,提出了一种降低运算复杂度并加快译码速度的新颖分组Turbo码(BTC)译码算法.与传统的Chase译码算法相比,该译码算法降低了译码复杂度且加快了译码速度.仿真分析表明,该算法较传统的Chase译码算法在误码率为10-6时提高了约1.15 dB的净编码增益(NCG),具有良好的纠错性能.因而它是一种适用于光传输系统且实用性较强的新颖BTC译码算法. 相似文献
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为了弥补Min-Sum译码算法相对于LLR-BP算法的性能缺陷,降低LLR-BP算法的实现复杂度,提出一种改进型Min-Sum译码算法,将Normalized BP-Based和Offset BP-Based 2种算法有效地结合,在计算校验节点消息时,同时引进校正因子和偏移因子,并通过最小均方差准则来选择参数。仿真结果表明,在误码率相同的条件下,改进型Min-Sum译码算法比Min-Sum算法、Normalized BP-Based算法和Offset BP-Based算法具有更好的译码性能,译码性能逼近于LLR-BP译码算法。 相似文献
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On algebraic soft-decision decoding algorithms for BCH codes 总被引:1,自引:0,他引:1
Kamiya N. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2001,47(1):45-58
Three algebraic soft-decision decoding algorithms are presented for binary Bose-Chaudhuri-Hocquengham (BCH) codes. Two of these algorithms are based on the bounded distance (BD)+1 generalized minimum-distance (GMD) decoding presented by Berlekamp (1984), and the other is based on Chase (1972) decoding. A simple algebraic algorithm is first introduced, and it forms a common basis for the decoding algorithms presented. Next, efficient BD+1 GMD and BD+2 GMD decoding algorithms are presented. It is shown that, for binary BCH codes with odd designed-minimum-distance d and length n, both the BD+1 GMD and the BD+2 GMD decoding algorithms can be performed with complexity O(nd). The error performance of these decoding algorithms is shown to be significantly superior to that of conventional GMD decoding by computer simulation. Finally, an efficient algorithm is presented for Chase decoding of binary BCH codes. Like a one-pass GMD decoding algorithm, this algorithm produces all necessary error-locator polynomials for Chase decoding in one run 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》1985,31(4):453-460
Universal decoding procedures for finite-state channels are discussed. Although the channel statistics are not known, universal decoding can achieve an error probability with an error exponent that, for large enough block length (or constraint length in case of convolutional codes), is equal to the random-coding error exponent associated with the optimal maximum-likelihood decoding procedure for the given channel. The same approach is applied to sequential decoding, yielding a universal sequential decoding procedure with a cutoff rate and an error exponent that are equal to those achieved by the classical sequential decoding procedure. 相似文献
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迭代检测技术不仅局限于在传统的级联码系统中的应用,还可用于解决现代数字通信中的许多检测/译码问题。随着Turbo码的出现,人们对迭代译码算法进行深入研究,并提出一些简化译码算法。比特交织编码调制及迭代检测(bit—interleaved coded modulation with iterative decoding,BICMID)是一种高效数据传输系统。比特交织和迭代译码是BICM—ID系统具有卓越性能的关键因素,译码算法的选择不仅影响接收机的性能,也决定了系统的复杂度。文中研究迭代译码算法对BICM—ID系统性能的影响,分析各种译码算法的计算复杂度。仿真结果表明log-APP算法有好的性能同时复杂度也高,简化的译码算法能降低译码器的复杂度,但会带来一定的性能损失;随着信道条件的改善,算法简化带来的性能损失也随之减小。 相似文献
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Takata T. Ujita S. Kasami T. Lin S. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1993,39(4):1204-1218
Multistage decoding of multilevel block multilevel phase-shift keying (M -PSK) modulation codes for the additive white Gaussian noise (AWGN) channel is investigated. Several types of multistage decoding, including a suboptimum soft-decision decoding scheme, are devised and analyzed. Upper bounds on the probability of an incorrect decoding of a code are derived for the proposed multistage decoding schemes. Error probabilities of some specific multilevel block 8-PSK modulation codes are evaluated and simulated. The computation and simulation results for these codes show that with multistage decoding, significant coding gains can be achieved with large reduction in decoding complexity. In one example, it is shown that the difference in performance between the proposed suboptimum multistage soft-decision decoding and the single-stage optimum decoding is small, only a fraction of a dB loss in SNR at the block error probability of 10-6 相似文献
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A new decoding method with decoder is used in open-loop all-optical chaotic communi-cation system under strong injection condition. The performance of the new decoding method is nu-merically investigated by comparing it with the common decoding method without decoder. For new decoding method, two cases are analyzed, including whether or not the output of the decoder is ad-justed by its input to receiver. The results indicate the decoding quality can be improved by adjusting for the new decoding method. Meanwhile, the injection strength of decoder can be restricted in a certain range. The adjusted new decoding method with decoder can achieve better decoding quality than decoding method without decoder when the bit rate of message is under 5 Gb/s. However, a stronger injection for receiver is needed. Moreover, the new decoding method can broaden the range of injection strength acceptable for good decoding quality. Different message encryption techniques are tested, and the result is similar to that of the common decoding method, indicative of the fact that the message encoded by using Chaotic Modulation (CM) can be best recovered by the new decoding method owning to the essence of this encryption technique. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》2008,54(9):3907-3928