Parameter estimation of multi-frequency signal based on 2D-spectrum

Spectrum leakage has considerable influence on the accuracy of spectrum analysis and signal parameter estimation. Many interpolation-based methods have been raised in order to restrain and diminish the influence of leakage on parameter estimation and spectrum correction. Those methods can improve the accuracy effectively but they can´t be theoretically immune to the leakage effect. In our work, an investigation is conducted that how DFT calculations distributed over the leakage spectrum of a sinusoid depends on the length of a windowed sinusoid. It is found that the leakage can be expressed by a sinc-function. Thus a set of functions can be constructed. Finally an approach in estimating parameters of multi-frequency signal with leakage is proposed. Experimental results suggest that the proposed algorithm is of validity and the numeric solutions are of high accuracy.