Patent ID: 7308033

Claim:
A method for tracking a residual frequency offset, comprising: (a) upon receiving a digital signal, determining a pilot from the values of data and known pilot data to be added, and adding the determined pilot to the leading part of the data; (b) performing a cyclic prefix for copying a part of a frame portion of the data after a first block in a unit of blocks having a fast Fourier transform (FFT) size and adding said part before the first block, generating a preamble to construct the blocks into one frame structure, adding a channel effect to the generated transmission frame, and sending the transmission frame: (c) eliminating a cyclic prefix (CP), processing signals received in the units of the FFT block, extracting the preamble, and performing an initial channel estimation; (d) updating the channel estimation according to a determined updating constant and an average phase of pilots, and performing channel compensation using the updated channel estimation; and (e) receiving a pilot portion output after the channel compensation, calculating an average phase of all the pilots in one FFT block, updating the channel estimation performing an inverse fast Fourier transform (IFFT) operation using the data and the pilot after channel estimation, extracting the data, and recovering the signal from the extracted data.