Multiple-access channel with delayed state information via directed information

A single-letter characterization is provided for the capacity region of finite-state multiple access channels using directed information. The channel state is a Markov process, the transmitters have access to delayed state information, and channel state information is available at the receiver. The delays of the channel state information are assumed to be asymmetric at the transmitters. We obtain the capacity region by innovative way, using a multi-letter expression for the capacity region of finite-state MAC with time-invariant feedback.