  We study non-commutative operator graphs generated by resolutions of identity
covariant with respect to unitary representations of a compact group. Our main
goal is searching for orthogonal projections which are anticliques
(error-correcting codes) for such graphs. A special attention is paid to the
covariance with respect to unitary representations of the circle group. We
determine a tensor product structure in the space of representation under which
the obtained anticliques are generated by entangled vectors.
