OFDM systems are vulnerable to time-selective fading effect, due to the relatively long symbol duration, compared with single-carrier systems. This results in non-negligible inter-carrier interference (ICI). This paper proposes an effective frequency-domain pilot-symbol-aided channel estimation method for fast-fading channels. By first observing high correlation between ICIs of adjacent subcarriers, we then devise an inter-carrier cancellation scheme. From the ICI-reduced signal, we are able to achieve good channel estimation and equalization accuracy. Simulations show that the new method can effectively combat fast-fading channel conditions. In addition, under the condition of using less pilots, the proposed method still can generate better SER than the current method .