Abstract
This paper deals with an identification method of peak frequency in spectrum of periodic wave. The phase of complex spectral components changes by π at the peak frequency. The inverse of the spectral component along the direction of its phase angle is plotted on a linear function of frequency bin number. The peak frequency is determined by interpolating this function. Actually the estimation of peak frequency is influenced by the other significant peaks. In order to increase the accuracy of frequency identification, these peaks have to be suppressed. This paper proposes a method to suppress them by adding data, shifted and multiplied by a specified phase term, to original data.
Experimental results show that peak frequency can be accurately identified from a short-time complex spectrum and the frequency of a weak peak in the sidelobe of a high spectral peak can be identified by suppressing the high peak. And it is also shown through the experiment that a four-tone chord performed by a musical instrument can be identified correctly from a 256-point spectrum.
