Blind Carrier and Sampling Frequency Offsets Estimation in OFDM System

This paper considers the blind estimation of the carrier frequency offset (CFO) and sample frequency offset (SFO) in orthogonal frequency division multiplexing (OFDM) system. Conventional methods require periodically transmitted pilot tones in frequency domain or identical training symbols in preamble. To achieve a blind estimation scheme, a joint maximum-likelihood (ML) estimator is proposed by applying another FFT within one symbol duration. Its simplified closed-form solution is then derived to reduce computational complexity. Theoretical analysis and simulation results confirm that the proposed low-complexity scheme achieves almost the same performance as ML estimation and outperforms other blind methods.