CAJ | 학술논문

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。
재현대통신중，유특비역마시일충흔호적규착역마방법，대신도차착적공제，강저오마솔，실현가고통신유중요의의。연이수착역마약속장도적증가기실현적복잡도장회대대적증가。통과개진적유특비역마산법，재가비선모괴시，설정일개문한화일개 N 치，계산매일보만족문한적로경수목，당기불만족여 N 치적관계시조정문한대소。저양매일상태선택최가능출현적약간조로경，종이감소당약속장도교대시역마적복잡도，실현쾌속역마。
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 Nvalue 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 with Nvalue, 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.