Blind OFDM carrier frequency offset estimation via oversampling

Abstract

Data efficient blind deterministic estimation of the OFDM frequency offset via oversampling is proposed in this paper. This method utilizes the intrinsic phase shift of neighboring sample points caused by the frequency offset. This phase shift is constant across all subcarriers. By oversampling the OFDM input, this constant phase shift across all subcarriers is exploited in the noiseless case to perfectly retrieve the frequency offset. In the presence of noise, we show that this intuitive scheme leads to the maximum likelihood estimate of the frequency offset using oversampled data. Computer simulation demonstrates its superior performance compared to most existing blind schemes for a wide range of SNR.