  A single-letter characterization is provided for the capacity region of
finite-state multiple-access channels, when the channel state process is an
independent and identically distributed sequence, the transmitters have access
to partial (quantized) state information, and complete channel state
information is available at the receiver. The partial channel state information
is assumed to be asymmetric at the encoders. As a main contribution, a tight
converse coding theorem is presented. The difficulties associated with the case
when the channel state has memory are discussed and connections to
decentralized stochastic control theory are presented.
