Unitary space-time constellations based on quasi-orthogonal sequences

In this paper, we propose a novel class of unitary space-time constellations based on quaternary quasi-orthogonal sequences (QOSs), minimizing the maximum correlation between the signal matrices. The proposed design, owing to the underlying algebraic structure of the QOSs, allows for an efficient decoder structure while offering performance virtually identical to the unitary space-time constellation design by Hochwald et al.