Hello, I want to use the LPC function to achieve AR pre-whitening, will the AR coefficient obtained by fftfilt filtering signal is a residual signal?

Hello, I want to use the LPC function to achieve AR pre-whitening, will the AR coefficient obtained by fftfilt filtering signal is a residual signal?Is the following code correct?

x = x - mean(x);

Na = 100; %It is assumed that Na is the AR model order of the maximum kurtosis of the residual signal

a = lpc(x,Na);

x = fftfilt(a,x);

x = x(Na+1:end); %Is the resulting x a residual signal? Or do you need to subtract this signal from the original signal to make a residual signal?

Answer 1

[Paul]

Hello Yx Y,

Based only on reading the lpc example, it would seem that the call to fftfilt should be

xest = fftfilt([0 -a(2:end)],x);
xest = xest(Na+1:end);

and the residual error would be

res  = xest - x(Na+1:end);

[Yx Y]

Ok, I will try the ideas you provided, thank you