Time delay estimation for weak signals with impulsive noises

Aiming to impulsive noises and low signal-to-noise ratio environment, a novel robust time delay estimation approach (referred to as the SR-FLOC) is addressed. Based on stochastic resonance technique and the fractional lower order covariance, the SR-FLOC can detect the delay of narrow-band signals with impulsive noises. Signal-to-noise ratio of the reference and detected signals is improved via the SR effect between noisy signals and bistable nonlinear dynamical systems. The SR effect is realized by tuning system parameters to their op ti ma l values under the maximum symmetric covariation coefficient criterion. Then the fractional lower order covariance function between outputs of two SR systems is computed. The delay is estimated by obtaining the location of this fractional lower order covariance function peak. The performance of the SR-FLOC algorithm is verified through computer simulations by using sin signals.