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:
Apr. 20, 1999
Filed:
Apr. 12, 1996
Applicant:
Inventors:
Assignee:
Transcrypt International/E. F. Johnson Company, Burnsville, MN (US);
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04Q / ;
U.S. Cl.
CPC ...
455 351 ; 455515 ; 379386 ;
Abstract
A transmit control system using in-band tones for activating and deactivating one or more remote sites. The transmit control system detecting energy in two or more spectral regions to determine if the signal received is a harmonic signal or a signalling tone to prevent accidental deactivation of the transmitter system. In one application, a modified Goertzel algorithm is employed by a digital signal processor to provide tone detection and a two stage detection provides controlled switching in noisy environments.