Second-Order Coding Rates for Channels With State

Marco Tomamichel, Vincent Yan Fu Tan

Abstract: We study the performance limits of state-dependent discrete memoryless channels with a discrete state available at both the encoder and the decoder. We establish the ε-capacity as well as necessary and sufficient conditions for the strong converse property for such channels when the sequence of channel states is not necessarily stationary, memoryless, or ergodic. We then seek a finer characterization of these capacities in terms of second-order coding rates. The general results are supplemented by several examples including independent identically distributed and Markov states and mixed channels.