Spectrum leakage suppression for multi-frequency signal based on DFT

This paper describes an innovative spectrum leakage suppression algorithm for the multi-frequency signal analysis. The proposed algorithm utilizes the all-phase pretreatment before Discrete Fourier transform (DFT) to reduce the spectral leakage by improving the signal continuity. In the all-phase pretreatment, signal samples are continuously cycle shifted, and a new signal sequence can be built by accumulating buffered signal sample sequences. The spectrum analysis of the multi-frequency signal is achieved by the Fourier transform of the constructed sequence. The spectrum leakage suppression algorithm is derived theoretically, and its superiority is verified by comparing with the traditional spectrum analysis based on the DFT with windowing in the experiments.