The problem of optimally detecting a desired BPSK modulated bit in the presence of two BPSK modulated interfering signals and additive white Gaussian noise is considered. Given certain information about the desired and interfering signals, the minimum achievable bit error rate (BER) is obtained and compared with that for a conventional matched filter. The optimal receiver is shown to offer a substantial performance advantage over the matched filter receiver when the interfering signal powers are large relative to the desired signal power.
