Note icceps only works on real data.x = icceps(xhat,nd) returns the inverse complex cepstrum of the real data sequence xhat, removing nd samples of delay. If xhat was obtained with cceps(x), then the amount of delay that was added to x was the element of round(unwrap(angle(fft(x)))/pi) corresponding to π radians.
x = icceps(xhat,nd)
You can give an example if you know one.