Zigangirov, K. Sh.; Chepyzhov, V. V. Existence of time-invariant convolutional codes with transmission rate \(2/c\) for \(c \geq{}4\) attaining the Costello bound. (English. Russian original) Zbl 0744.94011 Probl. Inf. Transm. 27, No. 3, 199-211 (1991); translation from Probl. Peredachi Inf. 27, No. 3, 16-29 (1991). A lower bound for the weights of codewords generated by time-invariant \((c,2)\)-convolutional encoders \((c\geq 4)\) is derived. From this lower bound it follows that there exist rate \(2/c\) convolutional codes whose free distance \(d_{free}\) asymptotically meets the Costello-bound. Reviewer: L.Staiger (Siegen) MSC: 94B10 Convolutional codes 94B65 Bounds on codes Keywords:free distance; lower bound; convolutional codes; Costello- bound PDF BibTeX XML Cite \textit{K. Sh. Zigangirov} and \textit{V. V. Chepyzhov}, Probl. Inf. Transm. 27, No. 3, 199--211 (1991; Zbl 0744.94011); translation from Probl. Peredachi Inf. 27, No. 3, 16--29 (1991)