MULTI-FREQUENCY TONE DETECTOR

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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