Performance of an integer carrier frequency offset estimation method in OFDM Systems

In this paper, an integer carrier frequency offset estimation method, based on the spectrum of a demodulated measurement, was studied and compared with another method, based on the null subspace spectrum of a measurement, by theoretical analysis and simulation. The impact of the fractional carrier frequency offset estimation is also studied. Contrary to the conclusion drawn by the authors of the former method, it is discovered, in this paper, that the former performs much worse than the latter for SUI-3 channels and Rayleigh channels, because its selection rule on null subcarriers, given by the demodulated measurement spectrum, is much more sensitive to channel deep fades. It is also proved in this paper that the former does not offer significant computational advantage over the latter.