Orthogonal Frequency Division Multiplexing (OFDM) is of great interest for the development of fifth generation technology. It is the cornerstone of Multiple-input multiple-output (MIMO) systems. Even though inter carrier interference (ICI) and inter symbol interference (ISI) have been processed for fourth-generation standards, they still present a huge problem for fifth generation standards. This paper explores the tradeoff between the length of the cyclic prefix and the performances of the OFDM system. It studies the effect of carrier frequency offset (CFO) on OFDM systems. A blind frequency offset estimator that uses the correlations between the remodulated sequence in the receiver side and the conventional received symbol are presented and a closed form solution is derived. The proposed estimator is derived under short interval when the correlation is high, so it has low computational complexity. Lin and Beek’s estimators are used for comparison. Simulations demonstrate the effectiveness of the proposed estimator under Rayleigh fading channel.
carrier frequency offset (CFO); orthogonal frequency division multiplexing (OFDM); inter-carriers interference (ICI); AWGN channel; rayleigh fading channel.