Strengthened lower bound on definite decoding minimum distance for periodic convolutional codes (Corresp.)

A new lower bound on definite decoding minimum distance for the class of systematic binary periodic convolutional codes is presented. The bound is everywhere stronger than Wagner´s bound and has the same form as the bound obtained by Massey for the class of systematic binary fixed convolutional codes. The bound is also shown to apply to a specific subclass of simply implemented periodic codes for which Wagner´s bound also holds.