An Outer Bound for Multiple Access Channels withCorrelated Sources

摘要

The capacity region of the multiple access channelrnwith correlated sources remains an open problem. Cover,ElrnGamal and Salehi gave an achievable region in the form of singleletterrnentropy and mutual information expressions,without arnsingle-letter converse. Cover,El Gamal and Salehi also suggestedrna converse in terms of some n-letter mutual informations,whichrnare incomputable. We have proposed an upper bound for thernsum rate of this channel in a single-letter expression,by utilizingrna new necessary condition for the Markov chain constraint onrnthe valid channel input distributions. In this paper,we extendrnour results from the sum rate to the entire capacity region. Wernobtain an outer bound for the capacity region of the multiplernaccess channel with correlated sources in finite-letter expressions.