Harmonic Vector Excitation Coding Of Speech At 2.0-4.0 Kbps

A low rate speech coding algorithm, Harmonic Vector Excitation Coding (HVXC) [ 13 is proposed for MPEG-4 standardization, in which combination of weighted vector quantization of harmonic spectral envelope of LPC residual signal for voiced segments [2] and vector excitation coding (VXC) for unvoiced segments are employed for 2.0 and 4.0 kbps coding. New features of the proposed coder includes a quantizer scheme capable of generating 2.0 and 4.0kbps scalable bit-streams, where 2.0 kbps decoding is possible using a subset of 4.0kbps bit-stream.