ML estimation of carrier frequency offset for multicarrier signalsin Rayleigh fading channels

摘要

In this paper, we present a new maximum likelihood estimator (MLE)nof carrier frequency offset for multicarrier signals in anfrequency-selective Rayleigh fading channel. The proposed MLE is able tonachieve wider estimation range of frequency offset with higher accuracynthan previous blind approaches by exploiting the intrinsic structure ofnmulticarrier signals. Simulations show that the estimation accuracy isnclose to the Cramer-Rao bound. In order to reduce the complexity of thenproposed MLE, a suboptimum technique is presented that enables simplenimplementation. The bit error rate performance of the suboptimumntechnique with two or three symbols averaged is close to the theoreticalnbound. An important feature of both the MLE and the suboptimum method isnthe capability to correct the frequency offset in a feedforward approachnthat makes it possible to perform fast acquisition and tracking of thenfrequency offset