Asynchronous multiple-access channel capacity
Thomas M. Cover, Robert J. McEliece, Edward C. Posner · IEEE Transactions on Information Theory · 1981
The capacity region for the discrete memoryless multiple-access channel without time synchronization at the transmitters and receivers is shown to be the same as the known capacity region for the ordinary multiple-access channel. The proof utilizes time sharing of two optimal codes for the ordinary multiple-access channel and uses maximum likelihood decoding over shifts of the hypothesized transmitter words.