An Accurate and Efficient Frequency Estimation Algorithm by Using FFT and DTFT

In this paper, a new algorithm of sinusoidal signal frequency estimation based on interpolation of Fast Fourier Transform (FFT) and Discrete-Time Fourier Transform (DTFT) is proposed. Firstly, A-point FFT is used to search the position of the maximum FFT spectrum line and get the rough frequency estimation. Then three DTFT spectrum lines located at any position within the main lobe is used to obtain the fine frequency estimation value. Next, in order to further improve the estimation performance, the proposed algorithm is combined with Candan algorithm. According to the simulation results, Root Mean Square Error (RMSE) of the proposed algorithm is significantly lower than Candan algorithm, RCTSL algorithm and A&M algorithm. In a wide range of Signal-to-Noise Ratio (SNR), the proposed algorithm is closer to the Cramer-Rao lower bound (CRLB) than the competitive algorithms. In terms of computation complexity, the proposed algorithm in this paper is lower than A&M algorithm, HAQSE algorithm and RCTSL algorithm.