一种基于LDPC编码系统的符号同步联合信噪比估计算法
doi: 10.3724/SP.J.1146.2006.00880
A Joint Timing Synchronization and SNR Estimation Algorithm for LDPC-Coded Systems
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摘要: 该文分析了符号同步误差和信噪比的初始估计对LDPC编码系统性能的影响，结合迭代译码输出软信息的统计特性，提出了一种由迭代译码软信息辅助的符号同步联合信噪比估计算法，通过两个紧密相关的环路，将符号同步，信噪比估计以及迭代译码三者整合在一起，在信噪比极低的情况下，通过迭代计算，信噪比和符号同步误差的估计值可快速收敛，译码性能接近信噪比已知且符号精确同步的编码系统。
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关键词:
- 低密度校验码;信噪比估计;符号同步
Abstract: The effects of both symbol synchronization error and SNR estimation on the LDPC decoding performance are investigated. Based on the statistical properties of the LDPC decoding output value, a joint timing recovery and SNR estimation algorithm is given, which puts the symbol synchronization, SNR estimation and iterative decoding together by two cooperative loops. After several iterative steps, the estimated values of symbol synchronization error and SNR convergent rapidly, and little performance degradation is observed than the system with foregone SNR and accurate symbol timing. -
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