• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Communications in Theoretical Physics >Code Optimization, Frozen Glassy Phase and Improved Decoding Algorithms for Low-Density Parity-Check Codes
【24h】

Code Optimization, Frozen Glassy Phase and Improved Decoding Algorithms for Low-Density Parity-Check Codes

机译：低密度奇偶校验码的代码优化，冻结玻相和改进的解码算法

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The statistical physics properties of low-density parity-check codes for the binary symmetric channel are investigated as a spin glass problem with multi-spin interactions and quenched random fields by the cavity method. By evaluating the entropy function at the Nishimori temperature, we find that irregular constructions with heterogeneous degree distribution of check (bit) nodes have higher decoding thresholds compared to regular counterparts with homogeneous degree distribution. We also show that the instability of the mean-field calculation takes place only after the entropy crisis, suggesting the presence of a frozen glassy phase at low temperatures. When no prior knowledge of channel noise is assumed (searching for the ground state), we find that a reinforced strategy on normal belief propagation will boost the decoding threshold to a higher value than the normal belief propagation. This value is close to the dynamical transition where all local search heuristics fail to identify the true message (codeword or the ferromagnetic state). After the dynamical transition, the number of metastable states with larger energy density (than the ferromagnetic state) becomes exponentially numerous. When the noise level of the transmission channel approaches the static transition point, there starts to exist exponentially numerous codewords sharing the identical ferromagnetic energy.
机译：通过腔法研究了具有多自旋相互作用和淬灭随机场的自旋玻璃问题，研究了二进制对称信道的低密度奇偶校验码的统计物理性质。通过评估Nishimori温度下的熵函数，我们发现，与具有均匀度分布的常规对应项相比，具有校验（位）节点异质度分布的不规则构造具有更高的解码阈值。我们还表明，仅在熵危机之后才发生平均场计算的不稳定性，这表明在低温下存在冻结玻璃态相。当没有假定先验的信道噪声知识（搜索基态）时，我们发现对常规置信传播的强化策略将使解码阈值提高到比常规置信传播更高的值。该值接近动态转换，在动态转换中，所有本地搜索试探法都无法识别真实消息（代码字或铁磁状态）。在动态过渡之后，具有更高能量密度（比铁磁态大）的亚稳态态的数量成倍增加。当传输信道的噪声水平接近静态转变点时，就开始以指数形式存在大量共享相同铁磁能的码字。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号