Reconstruction of convolutional encoders over GF(q)

Eric Filiol

BP 105
78153 Le Chesnay Cedex, France
Ecoles Militaires de Coëtquidan, DGER/CREC
56381 Guer Cedex, France

Cryptography and Coding - Sixth IMA Conference, LNCS 1355, pages 101-109.
Springer-Verlag, 1997.


Assuming we only have the coded sequence produced by a convolutionnal encoder at one's disposal, is it possible to recover all the parameters defining this encoder? The implementation of such complete reconstruction for convolutionnal codes of any rate is presented in this paper, for both noiseless and noisy communications. Each time, several different solutions, i.e. alleged reconstructed encoders, are obtained, contrary to the awaited unicity. Their study yields a new characterization of convolutionnal codes along with some properties.