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:
Dec. 02, 1997
Filed:
Jun. 07, 1995
Yukimasa Sugino, Kanagawa, JP;
Yushi Naito, Kanagawa, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
A signal discrimination circuit for discriminating between a voice signal and a voiceband data signal that is transmitted over a telephone network. The signal discrimination circuit includes an electric power judgement unit, a zero-crossing number judgement unit, a sub-band power calculation unit, a tone detection unit, and a discriminated result output unit. The electric power judgement unit determines whether an input signal is a voice signal or a voiceband data signal based on an interblock electric power ratio of the input signal. The zero-crossing number judgement unit determines whether the input signal is a voice signal or a voiceband data signal based on a zero-crossing number of the input signal. The sub-band power calculation unit analyzes the input signal with a spectrum analyzer to generate a spectrum analyzed result and calculates sub-band powers using the spectrum analyzed result, and the tone detection unit determines a presence and absence of a tone signal based on the sub-band powers calculated by the sub-band power calculation unit. Based on determined results of the electric power judgement unit, the zero-crossing number judgement unit, and the tone detection unit, the discriminated result output unit determines whether the input signal is a voice signal or a voiceband data signal and outputs a judged result.