Rotationally invariant space time constellations

Abstract

The rotationally invariant space time constellation (RISTC) is defined. Both linear and affine constellations are studied. The RISTC is shown to be generalization of space time codes from the orthogonal design. A space time constellation is said rotationally invariant if for any pair in the set, the squared Euclidean distance is independent of the eigenvectors.