一种自适应维特比译码算法研究

An Adaptive Viterbi Decoding Algorithm

在现代通信中,维特比译码是一种很好的纠错译码方法,对信道差错的控制,降低误码率,实现可靠通信有重要意义。然而随着译码约束长度的增加其实现的复杂度将会大大的增加。通过改进的维特比译码算法,在加比选模块时,设定一个门限和一个N值,计算每一步满足门限的路径数目,当其不满足与N值的关系时调整门限大小。这样每一状态选择最可能出现的若干条路径,从而减小当约束长度较大时译码的复杂度,实现快速译码。

In modern communications, viterbi decoding, as a fairly good error-correction decoding method, could control the channel errors, reduces the code error rate, and ensures the stable communication. However, with the increasing of decoding constraint length, the decoding complexity is greatly raised. With a modified viterbi decoding algorithm, a threshold and a N value are set in ACSU module, and the number of path which satisfies the threshold could be calculated. If the number does not Satisfy the relationship withNvalue, the threshold size should be adjusted. Several best paths should be choosen in order to reduce the decoding complexity when the constraint length is fairly large, thus achieving rapid decoding.