In this work, four tracking schemes are analyzed for OFDM-based systems and simulation experiments are performed for an IEEE 802.11a WLAN system. The first scheme is a newly proposed symbol-by-symbol method, which estimates the carrier phase offset of each OFDM symbol and then appropriate compensation is made. The other three schemes, namely L-extension algorithm, D symbol algorithm and maximum likelihood estimation, estimate the residual carrier frequency offset and results are coupled to the local oscillator.