Statistical study of the delay variance estimation for the individual and global methods

When the variance of the delays is assumed to be relevant in a series of recurrent signals, two approaches are encountered. Either each delay is estimated allowing the computation of the sample variance (individual method) or the expected variance is directly estimated (global method). These two approaches are statistically compared using the global method introduced in a previous work and two individual methods: a Averaged Square Difference Function based estimator and a linear system based one. We finally show that the global method exhibits an interesting behaviour mainly due to its unbiasness.