( 4761 of 4761 ) |
United States Patent | 3,566,035 |
February 23, 1971 |
The periodicity or aperiodicity of a signal is determined, in a signal analyzer, from the so-called "cepstrum" of the signal; that is, from the Fourier transform of the logarithm of the power spectrum of the signal. The short-time cepstrum is obtained by passing the signal through a first spectrum analyzer followed by a logarithmic amplifier and a second spectrum analyzer. The cepstrum signal is characterized by a peak at a time proportional to the fundamental period during periodic portions of the signal, and by the absence of a peak during aperiodic portions of the signal.
Inventors: | A. Michael Noll (Newark, NJ), Manfred R. Schroeder (Gillette, NJ) |
Assignee: |
Bell Telephone Laboratories
(Incorporated,
New York)
|
Appl. No.: | 04/863,398 |
Filed: | July 17, 1969 |
Current U.S. Class: | 704/203 ; 324/76.21; 324/76.22; 704/207 |
Current International Class: | G10L 11/00 (20060101); G10L 11/04 (20060101); G10l 001/04 () |
Field of Search: | 179/1(AS),15.55 324/77(G) |
3168699 | February 1965 | Sunstein et al. |
proceedings of the symposium on TIME SERIES ANALYSIS, Murray Rosenblatt, . ed., CH 15., John Wiley and Sons, New York (Feb. 11, 1963). . NATURE, Article by J.S. Gill, Jan. 14, 1961, pgs. 117--119. . I.B.M. Technical Disclosure Bulletin, June, 1962, Vol. 5 No. 1, pgs. . 28--30.. |