Significance of Complex Group Delay Functions in Spectrum Estimation
K Nagi Reddy, S. Narayana Reddy, Arava Santosh Reddy · Signal & Image Processing An International Journal · 2011
This paper presents a method of spectrum estimation using second order group delay functions derived from the phase of the Fourier Transform (FT).The results obtained from the proposed method are compared with that of first order group delay function spectral estimation.This method provides better resolution with reduced variance and also suppresses the spikes generated due to noise in the spectrum compared to first order group delay functions spectral estimation.The spectral estimation is obtained using this method, the resolution properties of the periodogram estimation are preserved while the variance is reduced.Variance caused by the side lobe leakage due to windows and additive noise is significantly reduced even in the spectral estimate obtained using a single realization of the observation peak.This method works even for high noise levels (SNR = 0 dB or less).