In this letter, we derive a maximum likelihood receiver of binary phase shift keying signals over Nakagami-m distributed additive noise in power line communication system. The decision variable is characterized by using copula approach. The analytical average bit error rate of the considered scheme is numerically evaluated by using the cumulative distribution function of the decision variable. It is shown by simulations that the proposed receiver performs significantly better than an existing suboptimal receiver. © 2014 IEEE.