Accuracy of Three-Point Interpolated DFT Frequency and Damping Factor Estimators

In this paper the accuracies of three Interpolated Discrete Fourier Transform (IpDFT) estimators of real-valued undamped sinusoid frequency and damping factor are analyzed. One estimator has been already proposed in the literature, while the other two estimators are a generalization of published real-valued undamped sinusoid algorithms to real-valued damped sinusoids. All the analyzed algorithms use three interpolation points, and weight the analyzed signal by using a Maximum Sidelobe Decay (MSD) window. Moreover, they compensate the detrimental contribution of the fundamental image component on the estimated parameters. The accuracies of the proposed algorithms are then compared with each other through simulations when pure, noisy, and noisy and harmonically distorted damped sinusoids are processed.