Effects of prefiltering on model based tone frequency estimators

The performance improvement due to prefiltering of model based frequency estimators is investigated based on simulation experiments. Information available a priori or derived via initial estimates about the tone frequency locations is used to design a prefilter to remove noise and interference. The simulations indicate that prefiltering can improve the accuracy of such frequency estimators as Prony, Pisarenko, AR significantly. The improvements depend sensitively upon the accuracy of the initial information about the tone location. Interesting trade-offs between prefiltering gain and the gain due to subspace noise filtering have also been investigated