A note on duality and MacWilliams-type identities for convolutional codes

In English A recursion for sequences of spectra of truncated as well as tailbitten convolutional codes and their duals is derived. The order of this recursion is shown to be less than or equal to the rank of the weight adjacency matrix (WAM) for the minimal encoder of the convolutional code. It is enough to know a finite number of spectra of these terminated convolutional codes in order to obtain an infinitely long sequence of spectra of their duals.