A received OFDM signal is demodulated by sampling the OFDM signal at successive time instants and computing a Fourier transform of the samples for a block of time instants. In addition, a sliding Fourier transform is computed at every new one of the same input samples, to extract a pilot frequency tone. From results of the sliding Fourier transform a frequency error signal is detected. This signal is fed back the in a frequency synchronization feedback loop. The frequency synchronization feedback loop may be used to track the pilot tone by adjusting a phase correction signal and/or to track sample clock frequency variations.