Application of Linear Prediction Coefficients Interpolation in Speech Signal Coding

Abstract

Several interpolation techniques of linear prediction coefficients (LPC) for speech signal coding were experimentally analyzed. The obtained results show that direct interpolation of LPC can be applied for coding and decoding of significantly long segments of voiced speech. The best performance in sense of least number of unstable filters, smallest spectral distortions and greatest MOS score, was achieved when for interpolation were used linear and Hermite polynomials. Higher order interpolation polynomials such us cubic or third order splines, produced significant alternations in obtained LPC that led to worst results of the quality of the decoded speech. Also higher order polynomials without additional post processing of interpolated LPC produced more unstable filters. Ill. 5, bibl. 11 (in English; summaries in English, Russian, Lithuanian).