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.