Convex combination of direct frequency estimators

Direct frequency estimator (DFE) has recently been proposed for unbiased frequency estimation of a real tone in white noise. This paper proposes to improve the performance of the DFE using a convex combination of two DFEs. Each DFE is adapted independently to retain its performance advantage, and the estimation results are then adaptively combined for optimal performance. The convex combination scheme offers improved tracking and accuracy. Simulations show that the proposed estimator performs better than the conventional DFE.