Patent ID: 7133521

Claim:
An apparatus for feature processing of telecommunications signals, the apparatus being adapted to operate in a CELP domain without decoding to a speech signal domain the apparatus comprising: a dual-tone modulation frequency (DTMF) signal detection module, the dual-tone modulation frequency (DTMF) signal detection module being adapted to determine one or more DTMF tones based upon at least one or more mint CELP parameters, and the DTMF signal detection module being adapted to output the one or more DTMF signals if determined; a multi-input mixing module coupled to the DTMF signal detection module, the multi-input mixing module being adapted to process CELP parameters from more than one CELP-based codecs, representing respective more than one voice signals, into a single set of CELP parameters; wherein the dual-tone modulation frequency (DTMF) signal detection module comprises: a DTMF feature computation unit capable of receiving the one or more CELP parameters and external commands and computing one or more DTMF features, one or more DTMF feature pattern tables having one or more specific feature data corresponding to the one or more DTMF signals, a DTMF feature comparison unit, the DTMF feature comparison unit being adapted to process the one or more DTMF features derived from the DTMF feature computation unit with the one or more specific feature data in DTMF feature pattern tables to identify one or more DTMF specific signals and to classify the one or more DTMF specific signals, a DTMF feature buffer capable of storing the one or more DTMF feature parameters and the one or more DTMF classification data of one or more previous sub-frames or frames; a DMP decision unit capable of determining the one or more DTMF signals from DTMF classification data of a current and one or more previous sub-frames or frames according to one or more DTMF specifications and sending out the DTMF determined signals.