High temporal resolution in multi-pulse coding

A CELP (code-excited linear predictive) coder using code books populated with pulses generated using a higher time resolution than a classical multi-pulse system is proposed. The pulses in the code book are generated as sampled sinc pulses, which are allowed to attain their corresponding maximum values at positions not necessarily equal to sample positions. The proposed code book performs equally well as CELP coders using multipulse code books in terms of robustness toward corrupted speech. However, the speech obtained is smoother, and the number of pulses required per subblock can be reduced without degrading the speech quality. A preliminary estimation of the bit rate required indicates that a reasonable choice lies in the range 8-9 kb/s