2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/105370The necessary and sufficient conditions of optimality of the decoding of quantum signals minimizing the Bayesian risk are generalized for the Shannon mutual information criteria. It is shown that for a linear channel with Gaussian boson noise these conditions are satisfied by coherent quasi-measurement of the canonical annihilation amplitudes in the received superposition.6 pages. An addition to quant-ph/0511042Quantum Physicstext