公开(公告)号：US3629510A

公开(公告)日：1971-12-21

申请号：US3629510D

申请日：1969-11-26

Applicant: BELL TELEPHONE LABOR INC

Inventor： ANDERSON FREDERICK N ,  MILLER RALPH L

IPC: G10L25/90 ,  G10L1/02

CPC classification number: G10L25/90

Abstract: The fundamental period of a complex periodic signal may be determined by measuring the periods of individual harmonics of the periodic signal and finding their smallest common multiple. A useful display of harmonics and their submultiples is called a period histogram. Since the fundamental period in a period histogram is an integral multiple of a number of harmonics and is characterized by a maximum amplitude pulse, the time of occurrence of the first maximum pulse may be taken to represent the fundamental period of the complex periodic signal. However, because the largest peak of the histogram does not always correspond to the fundamental frequency of a wave, occasional errors in the indication of pitch may result. Such errors may be obviated by examining the pitch signal developed from a histogram measurement, applying logical tests to determine its acceptability and, if the indicated pitch is found to be unacceptable, by substituting a more acceptable value.

公开(公告)号：US3424869A

公开(公告)日：1969-01-28

申请号：US3424869D

申请日：1965-06-15

Applicant: BELL TELEPHONE LABOR INC

Inventor： ANDERSON FREDERICK N ,  KENNEDY RICHARD N ,  REED ROBERT A

IPC: H04J3/17 ,  H04B1/66

CPC classification number: H04J3/17 ,  H04J3/172