Patent ID: 11296739

Abstract:
A noise suppression device includes: a DFT executor that expands a baseband signal into a discrete Fourier series X0(n), the baseband signal being generated by mixing an AM broadcast wave signal including a carrier wave of the angular frequency ωC with a complex sine wave of the same frequency; and an amplitude spectrum calculator that calculates an amplitude spectrum |X0(n)| from X0(n). The noise suppression device also includes: an asymmetric component detector that detects an asymmetric component in |X0(n)|; a suppressor that calculates a discrete Fourier series X1(n) by multiplying the value corresponding to the asymmetric frequency bin by a first factor and multiplying the other values by a second factor in X0(n); and an IDFT executor that performs inverse discrete Fourier transform on X1(n) to obtain a discrete-time signal.