Frequency estimation using the analytic signals by decimation

An autoregressive (AR) spectral estimation method is presented for the improved estimation of two close sinusoidal frequencies. Instead of a conventional bandpass prefilter with real coefficients, a bandpass prefilter is used with complex coefficients for high resolution of the AR spectral estimation. Under the conditions that only the short data are given and the signal-to-noise ratio (SNR) is low, this method conquers some problems. A method is presented for further modifying this approach. The method effectively uses the remainder signals obtained after the down-sampling and repeats an estimation algorithm.<>