Parametric models of the magnitude/phase spectrum for harmonic speech coding
David L. Thomson · 2003
A method is described for representing magnitude and phase in a sinusoidal transform coder. Instead of transmitting individual sinusoids, the entire speech spectrum is transmitted. The synthesizer estimates the frequency, amplitude, and phase of each harmonic from the spectrum. Relatively high-quality speech in the 4.8-9.6 kb/s range is obtained by modeling the magnitude/phase spectrum with a combination of pole-zero analysis, phase prediction and vector quantization. A window subtraction method ensures proper synthesis of unvoiced speech. The system is robust since it does not depend on pitch estimates or voicing decisions.>