Robust LPC parameter estimation in standard CELP 4800 b/s speech coder

The application of robust LPC parameter estimation in standard CELP coders for secure communications, USA FED STD 1016 4.8 kb/s, for the purpose of decreasing LPC spectral degradation compared to the standard LPC methods is considered in the paper. Comparative experimental analysis is done referring to the results of three different spectral measures related to the RMS LOG spectral measure: likelihood ratios, cosh measure and cepstral distance. The experimental analysis justifies the use of the robust LPC methods in standard CELP speech coders.