In this paper an adaptive channel estimator is proposed and investigated to improve the performance of the receiver for pilot aided wireless and mobile OFDM systems. The estimator consists of a two-dimensional Wiener filter which is implemented as a cascade of two one-dimensional filters. We propose an efficient algorithm for adaptation to time varying channels of the second filter. The method is applied to the Terrestrial Digital Video Broadcasting System (DVB-T), which was originally specified for fixed receivers and which is in the process of being extended for mobile reception. The results are shown after inner decoding. Depending on the channel conditions, the signal-to-noise ratio gain can be up to 1.6 dB. The method provides a compatible improvement to DVB-T receivers.