HIGH SPEED LSP SAMPLING ALGORITHM OF VOCODER

摘要

PURPOSE: A high speed LSP sampling algorithm of a vocoder is provided to reduce a calculating time of a real root method which is used in a vocoder. CONSTITUTION: After odd numbered coefficients are firstly searched, even numbered coefficients are searched among the searched odd numbered coefficients. When searching the odd numbered coefficients, frequency bands are sequentially searched. Accordingly, most of a change time is spent to search the odd numbered coefficients. An LSP parameter is sensitive to a predetermined spectrum. A spectrum distortion of the LSP parameter is low. A searching time is reduced by differing an order of a searching section according to a distribution of the LSP parameter by 46% without sequentially searching a frequency band.