Biased estimation of symbol timing offset in OFDM systems

For orthogonal frequency division multiplexing (OFDM) receivers, the mutual orthogonality of the subcarriers is preserved only if the estimated symbol timing error lies in the lock-in region. This paper is the first to investigate adding a bias to coarse symbol time offset estimators, and analyze its performance in terms of the lock-in probability. The optimal value of the bias term is derived for unbiased symbol time offset estimators, and it is shown through simulation that the biased estimator achieves a significantly higher lock-in probability than the unbiased estimator.