METHOD FOR PRESUMING HARMONICS IN VOICE CODER

摘要

PURPOSE: A method for presuming harmonics in a voice coder is provided to remarkably reduce the volume of calculations by using delta adjustment for presuming spectrum harmonics of a voice signal in the voice coder. CONSTITUTION: An input signal spectrum is obtained by applying a window spectrum to an input voice signal(S40). A composite signal spectrum is attained by applying the window spectrum to a constant pitch candidate(S42). A difference between the absolute value of the input spectrum and the absolute value of the composite signal spectrum is squared to calculate an accumulated sum in each harmonic band to obtain an error energy of each band(S43). A harmonic frequency adjustment value that minimizes the error energy is calculated. The harmonic frequency adjustment value is applied to attain the magnitude of harmonic(S44).