An iterative code construction and codes generated by permutations for the asymmetric multiple-access channel

It is shown that for an asymmetric multiple-access channel, it is possible, starting with one codeword at each of the encoders, to add the codewords for one message at a time (first for the elements in the set of private messages and thereafter for the messages in the set of common messages) and to construct this way, iteratively, a code for this channel with the average error probability upper-bounded by an exponentially small quantity. Using this result, it is subsequently shown that a code for the asymmetric multiple-access channel can also be generated by only. a few (linear in the block length) permutations, still keeping the average error probability upper-bounded by the same error bound and in this way gaining storage space.