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Sampling Clock Offset (SCO) estimation is an important issue in Orthogonal Frequency-Division Multiplexing (OFDM) systems because sampling frequency mismatch between the transmitter and the receiver may severely degrade the system performance due to the loss of orthogonality between the subcarriers. SCO estimation in mobile environment is quite challenging since channel variation leads to an additional phase rotation that masks the SCO effects. However, most of the existing techniques rely on the assumption of a time-invariant channel and become considerably inaccurate in a mobile environment. In this paper, we propose an improvement to an existing pilot-aided SCO estimator aiming to provide robustness against channel variations. Performance was evaluated through simulations in an ISDB-T (Integrated Services Digital Broadcasting Terrestrial) compliant system and the results have shown a considerable improvement for all ranges of signal-to-noise ratios, specially for higher Doppler spread.