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:
Sep. 07, 1999
Filed:
Jun. 28, 1996
Robert J Burdge, Olathe, KS (US);
Steven P Poulsen, Lincoln, NE (US);
Transcrypt International, Inc., Lincoln, NE (US);
Abstract
An apparatus and method for creating voice privacy in electronic voice transmission systems includes the steps of digitizing an analog signal and inverting and rotating the frequency spectrum of the digitized audio signal. From the inverted and rotated spectrum, a complex signal is created from which the real component is extracted to produce a real signal suitable for transmitting. The processing method may optionally include the steps of translating the frequency of the signal spectrum, reducing the sampling rate, shifting the spectrum of the signal again, increasing the sample rate, and extracting the real part of the signal to produce a real signal. The digital signal processing is performed entirely with software. The scrambling and descrambling processes are identical, therefore, the same hardware and software may be used to scramble and descramble the signal.