Envelope and instantaneous phase considerations in speech modelling
A. Moreno, Miguel Angel Lagunas · 2003
The authors present a low-bit-rate coding system where the envelope and instantaneous phase of the residual are used. A time-varying filter (short-delay filter) is excited by a signal composed by a parametric version of the residual, multiplied by a sequence from a codebook. Two alternatives are studied for the design of the codebook: sequences formed by random pulses and sequences formed by random phases to simulate the instantaneous phase of the residual.>