On the capacity of the two-user M-ary multiple-access channel with feedback

A study is made of the Cover-Leung capacity region for two specific noiseless two-user M-ary input multiple-access channels with complete feedback. It is shown that the symmetric rate point of the Cover-Leung capacity region is on the total cooperation line for large enough values of M. Thus feedback allows communication at the same rates as if both users had complete joint knowledge of intended messages.