Abstract: An iterative structure is adopted to decode the codes at the decoder. A modified SOVA algorithm is presented, which is used to compute the soft output of the component decoders. The performance of the turbo-DFH system is simulated over AWGN channels. Simulation results show that the bit error rate performance of the turbo-DFH system is significantly better than that of the conventional DFH system with the Viterbi detection algorithm.