Patent ID: 7912709

Claim:
A method of estimating harmonic information and spectral envelope information of a speech signal, the method comprising the steps of: converting a received speech signal of a time domain to a speech signal of a frequency domain; calculating a coarse pitch value of the speech signal and determining a peak search range using the coarse pitch value; setting a plurality of peak search ranges in the speech signal, detecting peaks existing in each of the peak search ranges, determining a peak having the greatest spectral value among the detected peaks as a harmonic peak in each of the peak search ranges, and outputting the harmonic peak of each of the peak search ranges as harmonic information of the speech signal; and generating a harmonic spectral envelope by performing interpolation of the harmonic peaks, and outputting the generated harmonic spectral envelope as spectral envelope information of the speech signal, wherein the determined peak search range comprises a total interval, a shifting interval in which peak detection is not performed, and an actual search interval in which the peak detection is performed, the actual search interval is an interval excluding the shifting interval from the total interval, the total interval is determined to be greater than the coarse pitch value, and the shifting interval is determined to be less than the coarse pitch value, wherein when CP denotes the coarse pitch value, b denotes the total interval, and a denotes the shifting interval, the peak search range is determined by the equation below M ·CP< b< 2 m ·CP, 0 <a<m ·CP, where M<2m and 0<m<1<M.