System and method for performing predictive scaling in computing LPC speech coding coefficients

A system for generating linear predictive coding coefficients in response to a received speech signal waveform, comprising:

• a memory for storing matrix term data values corresponding to one or more matrices;
• an iteration means which performs iterations on said matrix term data values corresponding to said one or more matrices to generate linear predictive coding coefficients;
• a scaling factor generation block including an input for receiving a reflection coefficient, wherein said scaling factor generation block generates a scaling factor in response to said received reflection coefficient;
• a multiplier which receives said matrix term data values of said one or more matrices and which receives said scaling factor from said scaling factor generation block, wherein said multiplier multiplies said matrix term data values with said scaling factor to produce scaled data values;
• wherein said memory stores said scaled data values after operation of said multiplier;
• wherein said system is operable to generate a parametric representation of said speech signal waveform, wherein said parametric representation of said speech signal waveform includes said linear predictive coding filter coefficients.

A system for generating linear predictive coding coefficients in response to a received speech signal waveform, comprising:

• a gain generation block including an input for receiving a reflection coefficient and which generates a gain in response to said received reflection coefficient;
• a normalization block coupled to an output of said gain generation block, wherein said normalization output produces a multiplication factor and a shift factor;
• a multiplier which receives data values of said plurality of terms of said one or more matrices and which receives said multiplication factor from said normalization block, wherein said multiplier multiplies data values from each of said plurality of terms in said one or more matrices with said multiplication factor to produce a partially scaled data value;
• an adder which receives said shift factor value output from said normalization block and which produces a control signal;
• a barrel shifter for receiving said partially scaled data value, wherein said barrel shifter further includes a control input which receives said control signal from said adder and shifts said partially scaled data value according to said barrel shifter control signal to produce a substantially fully scaled data value;
• and
• a memory for storing said fully scaled data value;
• wherein said system is operable to generate a parametric representation of said speech signal waveform wherein said parametric representation of said speech signal waveform includes said linear predictive coding filter coefficients.

A method for generating linear predictive coding filter coefficients in response to a received voice signal waveform, comprising:

• receiving a voice signal waveform;
• generating one or more matrices comprising a plurality of terms, wherein said matrix terms comprise correlation coefficients, wherein said one or more matrices are generated in response to said received voice signal waveform;
• computing a reflection coefficient based on said received voice signal waveform;
• computing one or more iteration factors using said reflection coefficient;
• scaling said one or more iteration factors;
• performing an iteration on said terms in said one or more matrices using the reflection coefficient and said one or more iteration factors;
• wherein said iteration generally operates to reduce values of a plurality of said correlation coefficients in said one or more matrices, wherein said scaling said one or more iteration factors operates to increase the values of said plurality of terms in said one or more matrices to at least partially offset said reduction in values that occurs in said performing an iteration;
• storing said plurality of matrix terms in a memory using a fixed number of data bits after said performing an iteration and after said scaling;
• repeating said steps of computing a reflection coefficient, computing one or more iteration factors, scaling said one or more iteration factors, performing an iteration, and storing said plurality of matrix terms for a plurality of times to generate said linear predictive coding filter coefficients;
• and
• generating a parametric representation of said voice signal waveform, wherein said parametric representation of said voice signal waveform includes said linear predictive coding filter coefficients.