Minimum interference blind time-offset estimation for OFDM systems

This paper proposes a novel blind time-offset (TO) estimation scheme for orthogonal frequency division multiplexing (OFDM) systems. Based on the observation that a TO almost surely gives rise to interblock interference (IBI), the proposed TO estimation is accomplished by minimizing the IBI. Borrowing the idea of differential decoding, the need of channel state information is circumvented via joint processing of multiple received blocks. The proposed TO estimator is shown capable of offering reliable TO estimation with a small amount of received data. Unlike some existing blind TO estimators, it performs well in both frequency-flat and frequency-selective fading channels. More importantly, the proposed TO estimator is proved consistent. In addition, since most required computation can be done by using the fast Fourier transform, its computational complexity is fairly low. The merits of the proposed estimator are confirmed by both theoretical analysis and corroborating simulations.