A robust 800 bps MBE coder with VQ and MLP

A speech coding algorithm for a robust 800 bps coder has been developed based on the multi-band excitation (MBE) model. The techniques of smoothing the pitch period by dynamic programming, LPC all-pole model to approximate the MBE spectral shape, formant enhancement, interpolation, vector quantizer (VQ), and multilayer perception of neural networks (MLP), etc. are adopted to improve the performance while maintaining a very low bit rate speech coding. It can be implemented in real-time using a single chip ADSP2181 fixed point DSP. The synthesized speech is clear and intelligible. It is even intelligible in the presence of background noise at 80 dB.