Jointly and individually optimum receivers for BPSK signals in cochannel interference plus noise

In this paper, we consider the transmission of a binary phase shift keying signal in the presence of a single cochannel interferer and additive white Gaussian noise. The exact decision regions for individually optimum and jointly optimum receiver structures are determined. It is confirmed that jointly optimum receivers for this system have decision boundaries that are formed by straight line segments in two-dimensional signal space, while individually optimum receivers have curved decision boundaries. The error rate performances of both receivers are evaluated. The individually optimum receiver has better error rate performance, though the improvement over the jointly optimal receiver is negligible for most values of signal-to-noise ratio.