The free distance of a convolutional code is a reliable indicator of its performance. However its computation is not an easy task. In this paper, we present some algorithms to compute the free distance with good efficiency that work for convolutional codes of all rates and over any field. Furthermore we discuss why an algorithm which is claimed to be very efficient is incorrect.

翻译：卷积码的自由距离是衡量其性能的可靠指标，但其计算并非易事。本文提出若干高效算法，适用于任意域上任意码率的卷积码自由距离计算。此外，我们讨论了为何一种号称高效的算法存在错误。