Markov-Huffman coding of LPC parameters

The methods of Markov modeling and Huffman coding are combined to reduce the data rate of LPC-coded speech without any effect on the speech quality. A Markov model is applied to the quantization levels of the LPC parameters, and the transition probabilities are then used to generate Huffman coding tables. This procedure does not have any impact on speech quality since it affects only the representation of the quantized parameters. It is demonstrated that Markov-Huffman coding can lead to average savings of more than 20 percent in bit rate. A suboptimal scheme is also investigated, which can facilitate the implementation of the method on currently available signal processing chips.