gusucode.com > 信号处理工具箱 - signal源码程序 > signal\signal\signal\icceps.m
function x = icceps(xhat,nd) %ICCEPS Inverse complex cepstrum. % ICCEPS(xhat,nd) returns the inverse complex cepstrum of the % (assumed real) 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 pi radians. % % See also CCEPS, RCEPS, HILBERT, and FFT. % Author(s): T. Krauss, 2/22/96 % Copyright (c) 1988-98 by The MathWorks, Inc. % $Revision: 1.1 $ % References: % [1] A.V. Oppenheim and R.W. Schafer, Digital Signal % Processing, Prentice-Hall, 1975. if nargin<2 nd = 0; end logh = fft(xhat); h = exp(real(logh)+j*rcwrap(imag(logh),nd)); x = real(ifft(h)); function x = rcwrap(y,nd) %RCWRAP Phase wrap utility used by ICCEPS. % RCWRAP(X,nd) adds phase corresponding to integer lag. n = length(y); nh = fix((n+1)/2); x = y(:).' + pi*nd*(0:(n-1))/nh; if size(y,2)==1 x = x.'; end