Omar R. Al-Sammarraie and Mohamed G. El-Tarhuni
Carrier frequency oﬀset estimation, OFDM, synchronization, double-dwell
Frequency synchronization in orthogonal frequency division multi-plexing systems is very crucial to avoid degradation due to inter-carrier interference. In this paper, we introduce a new scheme for frequency synchronization that uses a pilot-based double-dwell search strategy to estimate the frequency oﬀset. The proposed algorithm exploits the predictability of the correlation function to narrow the search window and hence provide accurate estimation. Simulation results show that the proposed scheme achieves a signiﬁcant mean-square error performance gain of about one to two orders of magnitude compared to conventional cyclic-extension-based synchronization algorithms under ﬂat and frequency-selective Rayleigh fading channel conditions. The proposed scheme provides also a much lower complexity compared to single-stage search algorithms. Finally, it is shown that the proposed scheme has a robust performance while estimating the frequency error over a wide frequency range.