quin2
%
function [x] = quin2(Y) % Adapted by Eric Jacobsen, June, 2002. % % Y is a three-element complex vector with the % DFT output magnitude maximizer as the center element. % % Returns -0.5 < x < 0.5, which is the fraction of the sample % spacing (i.e., bin width) about the center element where the % peak is estimated to be. % % Ref: Quinn, BG, "Estimation of frequency, amplitude and phase % from the DFT of a time series," IEEE Trans. Sig. Proc. Vol 45, No 3, % Mar 1997, pp814-817. betam=real(Y(1)/Y(2)); betap=real(Y(3)/Y(2)); dm=-betam/(betam-1); dp= betap/(betap-1); kappap=(1/4)*log(3*(dp^4)+6*(dp^2)+1) - (sqrt(6)/24)*log(((dp^2)+1-sqrt(2/3))/((dp^2)+1+sqrt(2/3))); kappam=(1/4)*log(3*(dm^4)+6*(dm^2)+1) - (sqrt(6)/24)*log(((dm^2)+1-sqrt(2/3))/((dm^2)+1+sqrt(2/3))); delta=(dm+dp)/2 +kappap-kappam; x=delta; %