Time delay estimation for low SNR signals with impulsive noises using fractional low order covariation sequences

The time delay estimation is an active research topic in the field of signal processing. Aiming on signals are on the low SNR conditions, a novel adaptive time delay estimation method is presented by using the fractional low order statistics. First, the signal noise ratio is improved via computing the fractional low order cross-covariation between two received signals and the fractional low order auto-covariation of a received signal. Second, they are put into two adaptive filters. The difference between peak locations of two filter weight efficiencies indicates the relative time delay between two received signals when they are convergent under least mean square criteria. Computer simulation studies show that the estimation performance of the proposed method is good, especially under heavier impulsive noise or lower signal noise ratio.