Mode-based quantization of LP parameters for very low bit rate vocoder

This paper presents a new quantization algorithm for LP parameters, called mode-based quantization (MBQ), which is used in very low bit rate vocoders. The proposed quantization algorithm is designed for a particular kind of speech coder that is based on the multi-band model. In this algorithm, the mode information of a super-frame, which is composed of several consecutive frames, is applied to the quantization of LP parameters and thus results in a better quantization performance. The experiment results show that the proposed quantization algorithm quantizes the LP parameters effectively with greatly reduced coding bits.