A note on asymptotically catastrophic convolutional codes of rate (n-1)/n

Convolutional codes with rate R=(n-1)/n,n/spl ges/2, are defined in terms of their minimal parity check matrices. The matrices are represented by a binary vector notation introduced by Ytrehus (1992). The upper bounds on /spl omega/0 (minimum average weight per branch) are presented. Many classes of rate (n-1)/n convolutional codes are shown to be asymptotically catastrophic.