Novel Two-Point Interpolation DFT Method for Frequency Estimation of Sine-Wave Within a Short Time Window

The superiority of interpolated discrete Fourier transform (IpDFT) has been proven in frequency estimation. However, the effects of negative frequency and strong noise result in poor behavior when the length of the observation window is short. To this end, this paper proposes a novel two-point IpDFT method for frequency estimation based on rectangular window and zero padding technique. The proposed method exploits the conjugate symmetry and parity of the unbiased signal model. This is done to eliminate both short and long-range spectral leakage caused by positive and negative frequencies. Besides, the impact of white noise can be maximally resisted by using the rectangular window and zero padding technique. Simulation results demonstrate that the proposed method outperforms existing interpolated DFT methods.