METHOD AND APPARATUS FOR SEARCHING FIXED CODEBOOK HAVING LOW COMPLEXITY

摘要

PURPOSE: A method and an apparatus for searching a fixed codebook having low complexity are provided to remarkably reduce the quantity of calculations required for searching a fixed codebook of a vocoder. CONSTITUTION: A pulse position likelihood estimate vector size calculator(210) calculates the dimension of a pulse position likelihood estimate vector for each pulse position. A pulse position selector(220) selects M pulse positions having larger pulse position likelihood estimate vectors for tracks using absolute value information of likelihood estimate vectors. A full searching unit(230) perform full search for the pulse positions selected by the pulse position selector. An optimum pulse position selector(240) selects an optimum pulse position from the full-searched pulse positions.