Patent ID: 7308034

Claim:
A method for tracking a carrier frequency offset and a sampling frequency offset between a transmitter for concurrently transmitting subcarriers that have orthogonality and a receiver for receiving them, comprising: (a) detecting data received from the transmitter by using a first signal, and tracking a phase offset caused by the carrier frequency offset by using the detected received data; (b) detecting the data received from the transmitter by using the first signal, and tracking a phase offset caused by the sampling frequency offset by using the detected received data, including calculating a gradient value of a straight line that corresponds to the phase offset on the time axis by using a linear regression method that includes a phase offset estimate of a pilot signal located on a subchannel, a phase offset estimate of a data signal located on a subchannel, and an added weight; (c) compensating for the phase offset caused by the carrier frequency offset between the transmitter and the receiver according to the phase offset tracked in (a); and (d) compensating for the phase offset caused by the sampling frequency offset between the transmitter and the receiver according to the phase offset tracked in (b).