Cascaded Likelihood Vector-Compression of Linear-Predictive Models

Compression of linear-predictive spectra has applications in acoustics research, particularly, in communication of acoustical information. Cascaded likelihood vector compression (CLVC) is proposed for coding the spectral parameters of linear-predictive models at rates of 20 to 26 bits per model. The system is based on representing the LP all-pole model as a cascade of two lower-order models. The partitioning of the LP polynomial is done in the root domain by clustering the roots into two distinct groups. The compressor uses two codebooks to quantize each of the lower-order models.