Constructions and Restrictions for Balanced Splittable Hadamard Matrices

New Constructions of Balanced Quasi-Cyclic Generalized Hadamard Matrices

In this paper, we define quasi-cyclic (QC) generalized Hadamard matrices and balanced QC generalized Hadamard matrices. Then we propose a new construction method for QC generalized Hadamard matrices. The proposed matrices are constructed from the balanced optimal low correlation zone (LCZ) sequence set which has correlation value −1 within low correlation zone.

New Constructions of Quaternary Hadamard Matrices

In this paper, we propose two new construction methods for quaternary Hadamard matrices. By the first method, which is applicable for any positive integer n, we are able to construct a quaternary Hadamard matrix of order 2 from a binary sequence with ideal autocorrelation. The second method also gives us a quaternary Hadamard matrix of order 2 from a binary extended sequence of period 2 − 1, wh...

New restrictions on possible orders of circulant Hadamard matrices

We obtain several new number theoretic results which improve the field descent method. We use these results to rule out many of the known open cases of the circulant Hadamard matrix conjecture. In particular, the only known open case of the Barker sequence conjecture is settled.

Constructions of Complex Hadamard Matrices via Tiling Abelian Groups

Applications in quantum information theory and quantum tomography have raised current interest in complex Hadamard matrices. In this note we investigate the connection between tiling of Abelian groups and constructions of complex Hadamard matrices. First, we recover a recent very general construction of complex Hadamard matrices due to Dita [2] via a natural tiling construction. Then we find so...

Jacket matrices constructed from Hadamard matrices and generalized Hadamard matrices