Fast fading channels will result in the inter-carrier interference (ICI) and degrade the performance of orthogonal frequency division multiplexing (OFDM) systems. In this paper, a novel pilot pattern and corresponding channel estimation and data detection method for OFDM systems with fast fading channels have been proposed and investigated. The proposed pilot pattern is composed of two classical pilot patterns, which are the comb-type pilot pattern and the grouped pilot pattern. The proposed pilot pattern can reduce the required pilot number significantly compared with the grouped pilot pattern. Computer simulation show that the proposed channel estimation and data detection based on the proposed pilot pattern can eliminate the ICI effectively while achieving much lower pilot occupancy ratio per OFDM symbol than the grouped and equi-spaced pilot pattern.