Method and apparatus for DTMF detection and voice mixing in the CELP parameter domain

Abstract

A method and apparatus for DTMF detection and voice mixing in the code-excited linear prediction (CELP) parameter space, without fully decoding and reconstructing the speech signal. The apparatus includes a Dual Tone Multiplexed Frequency (DTMF) signal detection module and a multi-input mixing module. The DTMF signal detection module detects DTMF signals by computing characteristic features from the input CELP parameters and comparing them with known features of DTMF signals. The multi-input mixing module mixes multiple sets of input CELP parameters, that represent multiple voice signals, into a single set of CELP parameters. The mixing computation is performed by analyzing each set of input CELP parameters, determining the order of importance of the input sets, selecting a strategy for mixing the CELP parameters, and outputting the mixed CELP parameters. The method includes inputting one or more sets of CELP parameters and external commands, detecting DTMF tones, mixing multiple sets of CELP parameters and outputting the DTMF signal, if detected, and the mixed CELP parameters.

1 .- 9 . (canceled)  
     
     
         10 . The apparatus of  claim 35 , further comprising a transcoding module coupled to the DTMF detection module.  
     
     
         11 . (canceled)  
     
     
         12 . The apparatus of  claim 35 , wherein the DTMF signal detection module is provided in an advanced processing module, the advanced processing module being coupled to a transcoding module.  
     
     
         13 .- 14 . (canceled)  
     
     
         15 . The apparatus of  claim 35  wherein the DTMF signal detection module is incorporated within a CELP-based voice transcoder.  
     
     
         16 .- 21 . (canceled)  
     
     
         22 . The method of  claim 36 , wherein the CELP parameters include one or more of LSP information, pitch information, excitation vector information, energy information, fixed-codebook information, and silence description information.  
     
     
         23 .- 34 . (canceled)  
     
     
         35 . An apparatus for processing telecommunications signals, the apparatus comprising: 
 a dual-tone modulation frequency (DTMF) signal detection module, the dual-tone modulation frequency (DTMF) signal detection module being adapted to: 
 receive an input signal in a CELP-based domain, the input signal being represented by one or more input CELP parameters;  
 process information associated with the one or more input CELP parameters;  
 determine one or more DTMF tones based upon at least information associated with the one or more input CELP parameters;  
 output the one or more DTMF tones if determined;  
   wherein the one or more DTMF tones are associated with the input signal in the CELP-based domain.    
     
     
         36 . A method for processing telecommunications signals in a CELP based domain, the method comprising: 
 receiving an input signal in a CELP-based domain, the input signal being represented by one or more input CELP parameters;    processing information associated with the one or more input CELP parameters;    determining one or more DTMF tones based upon at least information associated with the one or more input CELP parameters;    outputting the one or more DTMF tones if determined.    wherein the one or more DTMF tones are associated with the input signal in the CELP-based domain.    
     
     
         37 . An apparatus for processing telecommunications signals, the apparatus being adapted to operate in a CELP based domain without decoding to a speech signal domain, the apparatus comprising: 
 a multi-input mixing module, the multi-input mixing module being adapted to: 
 receive one or more sets of CELP parameters from one or more CELP-based codecs, the one or more sets of CELP parameters representing respectively one or more signals;  
 process the received one or more sets of CELP parameters into a single set of CELP parameters;  
 output the single set of CELP parameters, the single set of CELP parameters representing a composite signal;  
   wherein the one or more sets of CELP parameters are processed into the single set of CELP parameters without decoding the one or more sets of CELP parameters into the speech signal domain, without mixing the one or more signals into the composite signal in the speech signal domain, and without encoding the composite signal from the speech signal domain into a CELP based domain.    
     
     
         38 . The apparatus of  claim 37 , further comprising a transcoding module coupled to the multi-input mixing module.  
     
     
         39 . The apparatus of  claim 37 , wherein the multi-input mixing module is provided in an advanced processing module, the advanced processing module being coupled to a transcoding module.  
     
     
         40 . The apparatus of  claim 37  wherein the multi-input module is incorporated within a CELP-based voice transcoder.  
     
     
         41 . A method for processing telecommunications signals in a CELP based domain, the method comprising: 
 receiving one or more compressed signals from one or more CELP-based coders, the one or more compressed signals including respectively one or more sets of CELP parameters;    processing the one or more compressed signals into a composite signal using the one or more sets of CELP parameters, the processing the one or more compressed signals including processing the one or more sets of CELP parameters into a single set of CELP parameters;    outputting the composite signal, the composite signal including the single set of CELP parameters;    wherein: 
 the processing the one or more compressed signals into a composite signal does not include decoding the one or more sets of CELP parameters into a speech signal domain;  
 the processing the one or more compressed signals into a composite signal does not include mixing the one or more compressed signals into the composite signal in the speech signal domain;  
 the processing the one or more compressed signals into a composite signal does not include encoding the composite signal from the speech signal domain into the CELP based domain.  
   
     
     
         42 . The method of  claim 41 , wherein the CELP parameters includes one or more of LSP information, pitch information, excitation vector information, energy information, fixed-codebook information, and silence description information.  
     
     
         43 . The method of  claim 41 , wherein the processing of multiple sets of CELP parameters is capable of mixing the CELP parameters of more than two input codecs.