Adaptive encoding of fixed codebook in CELP coders
نویسنده
چکیده
In this paper, we propose an adaptive encoding method of xed codebook in CELP coders and implement an adaptive xed code excited linear prediction (AF-CELP) speech coder. AF-CELP exploits the fact that the xed codebook contribution to speech signal is also periodic as the adaptive codebook (or pitch lter) contribution. By modeling the xed codebook with the pitch lag and the gain from the adaptive codebook, AF-CELP can be implemented at low bit rates as well as low complexity. Listening tests show that a 6.4 kbit/s AF-CELP has a comparable quality to the 8 kbit/s CS-ACELP.
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تاریخ انتشار 1998