Generalized time sharing: a low-complexity capacity-achieving multiple-access technique

It is shown that the encoding/decoding problem for any asynchronous M-user memoryless multiple-access channel (MAC) can be reduced to corresponding problems for at most 2M-1 single-user memoryless channels. This is done via a method called generalized time sharing that is closely related to a previously developed method called rate-splitting multiple access. These methods reduce the seemingly hard task of finding good multiple-access codes and implementable decoders for such codes to the much better understood task of finding codes and decoders for single-user channels. As a by-product, some interesting properties of the capacity region of M-user asynchronous discrete memoryless channels are derived.