Realtime implementation algorithm of CELP at 4.8 kb/s
Z.Y. Liu, Weizhi Zhu · 2002
A new kind of vector-excited speech coder, the pulse adaptive vector excited speech coder (PAVX), is proposed. The codebook of PAVX is obtained by a varying-threshold clustering algorithm using regular-pulse excitation sequences obtained from speech data. The optimal excitation search procedures become simple when a pulse adaptive method is used in matching the codebook. Moreover, the codebook efficiency of PAVX is four times as much as the basic CELP codebook. The computer simulation results show that at 4.8 kb/s, PAVX can produce a clear natural-sounding synthetic speech. This algorithm was implemented on one TMS320C25.>