Mismatched decoding and the multiple access channel

An achievable region is given for the multiple access channel under decoding mismatch conditions. It is shown that achievable rates higher than the random coding capacity of the single-user mismatched channel can sometimes be demonstrated by treating the single-user channel as a multiple access channel. Refining these ideas the author derives a lower bound on the capacity of the mismatched single-user channel, which is tighter than previously published bounds. The author also analyses the special case of minimum Euclidean distance decoding for the scaler and vector single-user additive noise channels, and for the multiple access additive noise channel