Estimating of coarse frequency offset in multicarrier receivers

摘要

A method and an apparatus for estimating coarse frequency offset in OFDM receiver are disclosed. The method for estimating coarse frequency offset includes the steps of: a) performing differential decoding process for two adjacent OFDM symbols obtained by performing FFT on the OFDM signal; b) obtaining candidate offset values by using L number of differential decoded values at the same position from the reference signal among differential decoded values; and c) estimating a coarse frequency offset according to positions on which the first and the second maximum values among the 2S+1 number of candidate offset values are present. The apparatus for estimating coarse frequency offset includes an input buffer, a complex multiplier, a storing unit, an address controller, a frequency offset acquisition unit and a frequency offset tracking unit. By the above construction, candidate offset values of constant range are directly obtained on the frequency domain posterior to the FFT processing by using the reference carrier signal inserted within OFDM frames and a coarse frequency offset is estimated within +/-1/2 range of intercarrier spacing. Accordingly, the stable and reliable frequency offset can be obtained.