Abstract: In order to enhance channel estimation performance of NC-OFDM systems in the case of lacking enough pilot symbols, a novel channel estimation scheme with modified noise reduction in transform domain is proposed. Channel multipath fading coefficients are estimated by inverse discrete Fourier transform (IDFT) in time domain based on the relationship between time and frequency domain expressions of the channel fading coefficients of NC-OFDM systems. Noise reduction filtering is performed in time domain. Finaly, the channel fading coefficients are obtained in frequency domain by discrete Fourier transform (DFT) without interpolation. Simulation results show the proposed channel estimation scheme outperforms the conventional LS estimation with a gain of about 4dB.