Invention Grant
- Patent Title: Multi-frequency tone detector
- Patent Title (中): 多频音检测器
-
Application No.: US12997991Application Date: 2008-06-30
-
Publication No.: US08457301B2Publication Date: 2013-06-04
- Inventor: Adrian Susan
- Applicant: Adrian Susan
- Applicant Address: US TX Austin
- Assignee: Freescale Semiconductor, Inc.
- Current Assignee: Freescale Semiconductor, Inc.
- Current Assignee Address: US TX Austin
- International Application: PCT/IB2008/052620 WO 20080630
- International Announcement: WO2010/001193 WO 20100107
- Main IPC: H04M3/00
- IPC: H04M3/00 ; H04M5/00

Abstract:
A tone detector for detecting a tone having a plurality of targeted frequencies comprises a first filter bank providing frequency estimates for an initial indication of a presence of each of the targeted frequencies; a second filter bank being controlled by the frequency estimates and comprising a plurality of filters operating in different frequency bands, each frequency band comprising at least one of the targeted frequencies, each of the filters providing a modified signal; a third filter bank extracting a noise signal from the input signal; a plurality of level control units (LCU) providing normalized modified signals having a constant amplitude; a power estimation module providing a power estimation parameter for each of the modified signals and the noise signal; and a discrimination module controlling a plurality of demodulator modules, each of the demodulator units providing a fine estimate of one of the targeted frequencies.
Public/Granted literature
- US20110103573A1 MULTI-FREQUENCY TONE DETECTOR Public/Granted day:2011-05-05
Information query