METHOD OF MULTI-PATH TRELLIS CODED QUANTIZATION AND MULTI-PATH TRELLIS CODED QUANTIZER USING THE SAME

摘要

A multi-path TCQ(Trellis Coded Quantization) method and a multi-path TCQ apparatus using the method are provided to enhance quantization efficiency at a low transmission rate and efficiently perform quantization of an input signal and a coefficient in a speech encoding system by using BC(Block constrained)-TCQ in order to improve quantization performance. Accumulation distortion corresponding to each of 2N survivor paths which enter to one of nodes of an Ith stage of trellis is calculated. Accumulation distortions respectively corresponding to the 2N survivor paths are compared, and N paths having smaller accumulation distortions are selected. The N paths are set as survivor paths entering an (I+1)th stage. The path having the smallest accumulation distortion is selected as a final path from 2N survivor paths connected to each of nodes of the last stage of the trellis.