A turbo coded hybrid ARQ with both IR and repetition existing in one or more transmission blocks is designed. The mixed combining is performed at the receiver—Chase combining is performed for the repetitions first, followed by code combining for all code bits based on Chase combining outputs. The packet error probability is obtained by applying the union-Bhattacharyya (UB) bound for parallel channels. The throughput optimization of hybrid ARQ is determined as well as the optimal assignment rates by solving the optimization using a genetic algorithm.