Error exponents of optimum decoding for the interference channel

Exponential error bounds for the finite-alphabet interference channel (IPC) with two transmitter-receiver pairs, are investigated under the random coding regime. Our focus is on optimum decoding, as opposed to heuristic decoding rules that have been used in previous works, like joint typicality decoding, decoding based on interference cancellation, and decoding that considers the interference as additional noise. Indeed, the fact that the actual interfering signal is a codeword and not an i.i.d. noise process complicates the performance analysis of the optimum decoder. In addition to the single-letter expressions of the error exponents derived, we also present some numerical results and discuss them.