The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 15, 1994
Filed:
Jul. 19, 1990
Applicant:
Inventors:
Robert W Horner, Whittier, CA (US);
Kheim V Cai, Brea, CA (US);
Ronald L Bergen, Irvine, CA (US);
Keith A Lane, Huntington Beach, CA (US);
Assignee:
Hughes Aircraft Company, Los Angeles, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G10L / ;
U.S. Cl.
CPC ...
381 46 ; 381 49 ;
Abstract
A waveform characterizer apparatus is disclosed for extracting cepstrum pitch and spectral properties of a waveform signal such as the baseband audio output of a receiver. The apparatus employs Fourier processing, cepstral processing, magnitude detection, logarithms processing, frequency selective filtering and time/frequency windowing to extract cepstrum pitch and spectral rolloff characteristics which can then be used to determine the signal type. One application of the invention is in a digital voice/squelch apparatus.