On Sylvester-type constructions of Hadamard matrices and their modifications

Using the ideas of concatenation construction of codes over the $q$-ary alphabet, we modify the known generalized Sylvester-type construction of the Hadamard matrices. The new construction is based on two collections of the Hadamard matrices. In particular this construction involves $m$ Hadamard matrices of order $k$ and $k$ Hadamard matrices of order $m$. These matrices are not necessary different. As a result we obtain a Hadamard matrix of order $km$. The new construction gives many possibilities for construction of the new Hadamard matrices with different ranks and dimension of kernel.