Capacity of the K-user Discrete Memoryless Multiple Access Channel with Common Information and with or without State

An explicit and efficient capacity characterization of the K-user discrete memoryless multiple access channel with common information and discrete memoryless state is provided. Messages are indexed according to which transmitters are aware of the messages, and any of 2(K) - 1 possible such messages may exist. A superposition coding scheme, which generalizes the approach taken by Slepian and Wolf for the two-user case without state, achieves this capacity region. When there is state, a separable coding scheme suffices to attain capacity.