Autocorrelation based carrier frequency offset estimator with extended frequency range

For bandwidth efficiency and burst transmission reason, the carrier frequency synchronization usually tends to be resolved by nondata aided frequency offset estimation technique. The autocorrelation based frequency offset estimators can achieve a mean square estimation error close to MCRB. However, the frequency ranges of this class of estimators are usually very poor, which badly limits their implementations. In this paper, the factors that limit the frequency range of an autocorrelation based estimator are discussed in detail. Based on that, an improved estimator scheme is proposed, which extends the estimation range to the upper bound of the frequency range for NDA estimator. Simulation results shows that the proposed scheme well addresses the frequency range extending whereas introduces no accuracy loss when E_s/N₀ is above the threshold.