Generalization of Feinstein´s fundamental lemma (Corresp.)

Given a channel and its input probability distribution, the fundamental lemma of Feinstein assures the existence of a code whose maximum error probability is bounded by a certain known constant. The lemma has been established for discrete-time channels and inputs that possess probability densities. We generalize the lemma for the case of continuous-time channels and inputs that do not possess probability densities.