Error Probability in Binary Digital Communication in the Presence of an Interfering Signal

The presence of an interferring signal i(t) in a binary coherent symmetric channel is investigated. The probability of error is maximum when i(t) is antipodal to the transmitted signal, so(t) or s1 (t). The error probability is derived in the presence of a delayed interfering signal - so (t - r), where r is the time delay. An example of phase shift keying signals is given.