An Approximate Method of Carrier Frequency Offset (CFO) Estimation for OFDM System

We investigate the problem of carrier frequency offset (CFO) estimation for orthogonal frequency division multiplexing (OFDM) systems. An approximated method for CFO estimation is derived. We show that the introduction of CFO can be taken as the result of passing through a frequency domain filter, whose coefficients are functions of CFO. To estimate the CFO, we construct an estimator based on the filter coefficients. In this way, the CFO estimation problem is converted to filter coefficients estimation. We also develop a fast algorithm with lower computational complexity. We show our method is effective for channel with large Doppler spread.