Short sample dense frequency signal parameter measurement method

The invention discloses a short sample dense frequency signal parameter measurement method, which comprises the following steps of: sampling an input analogue signal x(t) at an equal interval with sampling frequency fs to obtain 2N-1 discrete samples x(n); performing all-phase discrete Fourier transform (apFFT) on the x(n) to obtain a complex sequence Xa(k), obtaining amplitude spectrum by using the modulus of the Xa(k), and finding a spectral peak position k=k0; extracting a frequency range omega of [(k0-1)Deltaomega, (k0+2)Deltaomega] taking k0Deltaomega as a center, performing all-phase discrete Fourier transform (DTFT) on x(n) on the frequency range, and taking the phase spectrum of the transform, wherein Deltaomega is equal to 2phi/N; observing the characteristics of a phase spectrumcurve, and determining single-frequency condition if the phase spectrum curve presents straight distribution characteristics; if the phase spectrum curve presents continuous oscillation, determining dual-frequency distribution condition, and further estimating frequency, amplitude and phase values of two dense components; in addition, determining the multi-frequency conditions of component numbers more than or equal to 3. The method has the characteristic of accuracy controllability.