Patent ID: 6915224

Claim:
A method of spectrum analysis for analyzing a sample signal that is obtained by sampling an original signal at an original sampling rate within a sampling period, said method comprising the steps of: (a) Fourier transforming the sample signal into a spectrum to be measured according to a frequency range scale; (b) determining an optimum graduation interval of the frequency range scale in accordance with characteristics of the spectrum, the characteristics including at least one of frequency and amplitude parameters of the spectrum; (c) determining an updated sampling rate by multiplying the original sampling rate by the optimum graduation interval, and re-sampling the original signal at the updated sampling rate within the sampling period so as to obtain an updated sample signal; (d) obtaining an optimum sample signal by multiplying the updated sample signal by a scale shift function that is based on the optimum graduation interval and the characteristics of the spectrum; and (e) transforming the optimum sample signal into an optimized spectrum; wherein the original sampling rate is greater than twice a bandwidth of the original signal, and the sampling period contains at least three identical waveforms when the original signal is a periodic signal.