An intuitive justification and a simplified implementation of the MAP decoder for convolutional codes

被引：415

作者：

Viterbi, AJ ^{[1
]}

机构：

[1] Qualcomm Inc, San Diego, CA 92121 USA

来源：

IEEE JOURNAL ON SELECTED AREAS IN COMMUNICATIONS | 1998年 / 16卷 / 02期

关键词：

dual-maxima; MAP decoder; soft-decision metric; Viterbi algorithm;

D O I：

10.1109/49.661114

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

An intuitive shortcut to understanding the maximum a posteriori (MAP) decoder is presented based on era approximation. This is shown to correspond to a dual-maxima computation combined with forward and backward recursions of Viterbi algorithm computations, The logarithmic version of the MAP algorithm can similarly be reduced to the same form by applying the same approximation, Conversely, if a correction term is added to the approximation, the exact MAP algorithm is recovered, It is also shown how the MAP decoder memory can be drastically reduced at the cost of a modest increase in processing speed.

引用

页码：260 / 264

页数：5