In this paper, we propose a simple and robust iterative channel estimation algorithm in OFDM packet transmission systems. Iterative scheme with channel update process is effective to reduce the packet error rate. However, conventional iterative structure has a limit on improving the performance because error propagation often occurs while updating the channel in the low SNR. In order to overcome this problem, we introduce a novel moving average filter to enable estimating the channel more reliably. Simulation results show that the proposed algorithm outperforms the conventional scheme. In particular, combined performance of the proposed algorithm and the noise reduction method is close to MMSE channel estimation algorithm.