9.6/7.2 Kbps Voice excited predictive coder (VEPC)

This paper describes a common voice coding architecture based on a Voice Excited Predictive Coding (VEPC) scheme allowing operation at different bit rates : 9600, 7200 bps or below by simply modifying the bandwidth allocated to the coding of the baseband excitation signal. This coding scheme, in addition to the baseband excitation concepts, takes advantage of the association of recently published digital speech processing techniques such that transversal predictive coding, splitband coding by signal decimation/interpolation and adaptive block quantization. Simulations have shown that the proposed architecture allows to obtain a 'standard telephone quality' assuming a 300-3400 Hz telephone bandwidth at transmission rates below 9600 bps.