New multistage scheme for vector quantisation of PARCOR coefficients

A new multistage scheme for vector quantisation of PARCOR coefficients for low bit rate speech coding is proposed. The novelty of this scheme is that the lattice filter structure is preserved after the quantisation. This is achieved by coupling the forward and backward prediction errors across vector quantisation (VQ) stages. Simulation results show that the new scheme can achieve lower average distortion than other multistage VQ schemes.