Convergence behavior of iterative source-channel decoding
Convergence behavior of iterative source-channel decoding
复制标题
迭代源通道解码的收敛行为
DOI：
10.1109/icassp.2003.1202619
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
P. Vary
中科院分区：
文献类型：
--
作者：
M. Adrat;Ulrich von Agris;P. Vary
每当数字通信遭受传输错误时，在接收机处利用可靠性信息是有益的。软信道译码技术提高了纠错能力，此外，软比特信源译码执行错误隐藏。虽然信道解码的可靠性增益是基于在发射机处显式引入的人工冗余，但软比特源解码利用了在最先进的源编码之后比特流中剩余的隐式冗余。在迭代信源信道解码方案中，为了增强共同的抗误码能力，两者的可靠性增益被迭代地交换。然而，第一次调查表明，有利可图的迭代次数是有限的小值。在本文中，收敛行为进行了分析，使用一个现代的工具，称为EXIT图。EXIT图允许我们通过研究单个组件来预测收敛行为。作为一种新奇，EXIT特性被指定用于软比特源解码。通过仿真验证了算法的收敛性。
Whenever digital communication is subject to transmission errors, the utilization of reliability information at the receiver is beneficial. Soft-channel decoding techniques improve the error correcting capabilities and in addition, softbit source decoding performs error concealment. While the reliability gain of channel decoding is based on artificial diversities explicitly introduced at the transmitter, softbit source decoding exploits implicit redundancies remaining in the bitstream after state-of-the-art source encoding. In an iterative source-channel decoding scheme the reliability gains of both are exchanged iteratively in order to enhance the common error resistance. However, first investigations have shown that the number of profitable iterations is limited to small values. In this paper, the convergence behavior is analyzed using a modern tool called EXIT charts. EXIT charts permit us to predict the convergence behavior by studying the individual components. As a novelty, EXIT characteristics are specified for softbit source decoding. The convergence analysis is confirmed by simulation.