Low rate sinusoidal coding of speech using an improved phase matching algorithm

A new phase model for low-bit rate sinusoidal coding of speech is presented. Short-time sinusoidal phases are approximated using a combination of linear prediction, spectral sampling, delay compensation, and phase correction techniques. The algorithm is different than phase compensation methods proposed for source-system LPC in that it has been tailored to sinusoidal representation of speech. Performance analysis on a large speech database indicates considerable improvement in temporal and spectral signal matching as well as improved subjective quality of the reconstructed speech. The extra parameters used for representation of the sine wave phases require a small number of bits. The method can be applied to enhance phase matching in low bit rate sinusoidal coders, where underlying sine wave amplitudes are extracted from an all-pole model.