专利名称:MULTI-FREQUENCY TONE DETECTOR发明人:SUSAN, Adrian申请号:EP08776559.0申请日:20080630公开号:EP2294832B1公开日:20120111
摘要:A tone detector (10) for detecting a tone having a plurality of targeted
frequencies comprises a first filter bank (12) providing frequency estimates (16, 18) for aninitial indication of a presence of each of the targeted frequencies; a second filter bank(20,22) being controlled by the frequency estimates (16,18) and comprising a plurality offilters (20,22) operating in different frequency bands, each frequency band comprising atleast one of the targeted frequencies, each of the filters providing a modified signal(24,26); a third filter bank (28,30) extracting a noise signal (32) from the input signal; aplurality of level control units (LCU) (34,36) providing normalized modified signals (38,40)having a constant amplitude; a power estimation module (42) providing a powerestimation parameter (44,46,48) for each of the modified signals (24,26) and the noisesignal (32); and a discrimination module (50) controlling a plurality of demodulatormodules (52,), each of the demodulator units providing a fine estimate (56,58) of oneof the targeted frequencies.
申请人:FREESCALE SEMICONDUCTOR INC
地址:US
国籍:US
代理机构:Ferro, Frodo Nunes
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