A real time 8 kbps full-duplex vocoder using Joint-Excitation Linear Predictive Coding (JELPC) scheme is presented. JELPC utilizes a self excitation sequence for long term prediction in addition to two codebooks populated with stochastic distributions (one with multi-pulse entries and another with full entries) to model the excitation signal. With these special codebook structures and an efficient codebook searching algorithm, the coder complexity is reduced significantly and well suited for real time applications. The algorithm was implemented using a single TMS320C25 based DSP board, and has been shown to generate high quality speech. The details of the hardware architecture, algorithm implementation and system performance are also addressed clearly in this paper.
Bibliographic reference. Law, K. W. / Wong, O. Y. / Chan, C. F. (1991): "A real-time high quality joint-excitation linear predictive coder at 8 kbps", In EUROSPEECH-1991, 821-824.