A New Lower Bound on Error Probability for Nonuniform Signals over AWGN Channels

A recently published lower bound on the probability of a finite union of events, which is referred to in this paper as the new FLS lower bound, is applied to find a lower bound of the average symbol detection error rate of nonuniform M-ary modulated signals transmitted over the additive white Gaussian noise channels. An optimum detector based on the maximum a posteriori principle is assumed. Numerical results are presented to show that, when compared with the best known de Caen lower bound and the KAT lower bound in the literature, the new FLS lower bound always provides the tightest estimation of the average symbol detection error rate for both uniform and nonuniform signallings.