A novel frequency estimation of sinusoidal signal by noise approximation

Abstract

This paper presents a method for estimating the frequency of sampled sinusoidal signal. Firstly, the coarse estimate of frequency is obtained by discrete Fourier transform and then a reference signal is constructed with the estimated value. By conjugate multiplying the reference signal and the original signal, a new sinusoidal signal is obtained. Through superimposing the new signal sequence, the Signal-to-Noise ratio (SNR) is improved. When SNR»1, the additive noise can be considered as an equivalent phase noise. Based on the designed optimal superimposition, the frequency of the new signal can be obtained by Least-Square estimation. Theoretical analysis and simulation results show the performance of proposed method is closed to the Cramer-Rao bound with low complexity.