ML estimation of timing and frequency offset using multiple OFDM symbols in OFDM systems

An approach of joint blind estimation of the symbol timing offset and carrier frequency offset using multiple orthogonal frequency-division multiplexing (OFDM) symbols is proposed for OFDM systems in frequency selective fading environments. The proposed approach greatly improves the estimation accuracy of the synchronization parameters, more than the ML estimation of N. Lashkarian and S. Kiaei (see IEEE Trans. Commun., vol.48, p.2139-49, 2000). This conclusion is derived from analyzing their performances. Meanwhile, simulation shows that estimation of symbol timing is completely correct for signal-to-noise ratio (SNR) as low as 0 dB, and the variance of the frequency offset estimator is nearly close to its Cramer-Rao bound (CRB) with varying SNR.