A new intuitive result for the BEP of a jointly optimal single cochannel interferer BPSK receiver

A new and intuitive expression for the bit error probability (BEP) of a two-user synchronous jointly optimum receiver in an additive white Gaussian noise (AWGN) channel is derived. The desired and interfering users are assumed to use binary phase-shift keying (BPSK) modulation. The new expression decomposes into the BEP of BPSK in AWGN plus a term due to the interference. It is shown that the term due to interference vanishes when the interference power or its correlation with the desired signal tends to zero.