A Lower Bound on the Probability of Undetected Error for Binary Constant Weight Codes

In this paper, we study the probability of undetected error for binary constant weight codes (BCWCs). First, we derive a new lower bound on the probability of undetected error. Next, we show that this bound is tight if and only if the BCWCs are generated from certain t-designs. This means that such BCWCs are uniformly optimal for error detection. Thus, we prove a conjecture of Xia, Fu, Jiang and Ling. Furthermore, we determine the distance distributions of such BCWCs. Finally, we derive some bounds on the exponent of the probability of undetected error for BCWCs. These bounds enable us to extend the region in which the exponent of the probability of undetected error is exactly determined