Patent ID: 7206739
Filing Date: 2007-04-17
Classification: G10L

Abstract:
1. A method for segmenting a speech signal frame into a plurality of subframes to generate an excitation signal to be used in a synthesis filter, segmenting each of the plurality of subframes into a plurality of subgroups, and searching the respective subframes each comprised of a plurality of pulse position and amplitude combinations for pulses in a speech coding system including the synthesis filter for synthesizing a speech signal, comprising the steps of: searching the respective subgroups for positions and amplitudes of N selecting a pulse combination including at least one pulse representing position and amplitude among the pulses of the initial vector; and substituting the pulse position and the amplitude of the selected pulse combination for positions and amplitudes of other pulses in the respective subgroups; wherein the selecting and substituting steps are repeatedly performed on all the pulses and the amplitudes of the initial vector, and positions and amplitudes of pulses having a maximum cost function value J=(C) where m i represents a position of an i th pulse, and θ i represents an amplitude of an i th pulse, h(n) represents an impulse response of the synthesis filter, x(n) represents a target signal for an adaptive codebook search, d(n) represents elements of a cross-correlation matrix d=H T x 2 , x 2 represents a target function of a perceptual domain, and H represents an impulse response function.