  Maximum distance separable convolutional codes are the codes that present
best performance in error correction among all convolutional codes with certain
rate and degree. In this paper, we show that taking the constant matrix
coefficients of a polynomial matrix as submatrices of a superregular matrix, we
obtain a column reduced generator matrix of an MDS convolutional code with a
certain rate and a certain degree. We then present two novel constructions that
fulfill these conditions by considering two types of superregular matrices.
