Frequency domain adaptive filter system with second-order sliding discrete fourier transform

The invention provides a frequency domain adaptive filter system with second-order sliding discrete Fourier transform. The frequency domain adaptive filter system includes a second-order sliding discrete Fourier transform device, a normalized device, an adaptive filtering device, and a summation device. The second-order sliding discrete Fourier transform device receives N time-domain input signals, and performs a sliding discrete Fourier transform to generate N frequency-domain input signals. The normalized device is connected to the second-order sliding discrete Fourier transform device to receive the N frequency-domain input signals for performing the normalization operation on the N frequency-domain input signals and generating a plurality of normalized signals. The adaptive filtering device is connected to the normalized device for performing filtering operation of the plurality of normalized signals to generate a plurality of filtered signals. The summation device is connected to the adaptive filtering d