rceps (Signal Processing Toolbox)

Real cepstrum and minimum phase reconstruction

Syntax

Description

The real cepstrum is the inverse Fourier transform of the real logarithm of the magnitude of the Fourier transform of a sequence.

Note rceps only works on real data.

rceps(x) returns the real cepstrum of the real sequence x. The real cepstrum is a real-valued function.

[y,ym] = rceps(x) returns both the real cepstrum y and a minimum phase reconstructed version ym of the input sequence.

Algorithm

rceps is an M-file implementation of algorithm 7.2 in [2], that is,

Appropriate windowing in the cepstral domain forms the reconstructed minimum phase signal:

w = [1; 2*ones(n/2-1,1); ones(1 - rem(n,2),1); zeros(n/2-1,1)];
ym = real(ifft(exp(fft(w.*y))));

See Also

cceps, fft, hilbert, icceps, unwrap

References

[1] Oppenheim, A.V., and R.W. Schafer, Digital Signal Processing, Englewood Cliffs, NJ, Prentice-Hall, 1975.

[2] Programs for Digital Signal Processing, IEEE Press, New York, 1979.

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