Hybrid Log-MAP Algorithm for Turbo Decoding Over AWGN Channel
Hybrid Log-MAP Algorithm for Turbo Decoding Over AWGN Channel
复制标题
用于 AWGN 信道 Turbo 解码的混合 Log-MAP 算法
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
G. Lim
中科院分区：
文献类型：
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作者：
Li Li Lim;David Wee;G. Lim
在Log-MAP Turbo译码中，复杂的对数指数和常常被简化为雅可比对数，该对数由最大运算和指数校正函数组成。虽然Max-Log-MAP通过省略校正函数降低了雅可比对数实现的复杂度，但其性能不如精确的Log-MAP算法。因此，需要对校正函数进行简单的近似来补充Max-Log-MAP算法。提出了一种新的次优混合Log-MAP Turbo码译码算法。该算法逼近精确的对数映射，硬件实现简单。结果表明，混合Log-MAP算法的性能与精确的Log-MAP算法最接近，尤其是在低信噪比时。文中还给出了其他基于Log-MAP算法的实验结果。索引项-对数映射、Turbo码、校正函数、雅可比对数。
In Log-MAP turbo decoding, the complicated log exponential sum is often simplified with the Jacobian logarithm which consists of the max operation along with an exponen- tial correction function. Although the Max-Log-MAP reduces the complexity of the Jacobian logarithm implementation by omitting the correction function, its performance is inferior to the exact Log-MAP algorithm. Hence, a simple approximation to the correction function is needed to complement the Max- Log-MAP algorithm. In this paper, a new suboptimal hybrid Log-MAP algorithm for decoding turbo code is proposed. It approximates the exact Log-MAP accurately and is simple for hardware implementation. The performance of the hybrid Log- MAP algorithm is shown to have the closest performance to the exact Log-MAP solution especially at low SNR. The result of other Log-MAP based algorithm are also presented. Index Terms—Log-MAP, turbo codes, correction function, Jacobian logarithm.