Patent ID: 8385834

Claim:
A radio receiving apparatus having a noise elimination circuit for removing a pulse-like noise component of a radio input audio signal, the radio receiving apparatus comprising: a control section for making a decision of waveform symmetry in amplitude positive and negative directions with respect to a center value in values input to said noise elimination circuit of the pulse-like noise component from Fourier spectrum distribution, and for stopping operation of the noise elimination circuit when a decision of a symmetric wave is made, the control section including a functional operation section for calculating coefficient distribution of harmonics by performing Fourier series expansion of the pulse-like noise component, wherein the Fourier series expansion has, as a basic period, time intervals which are equal to or longer than several tens times pulse width of the pulse-like noise component; and a comparison operation section for comparing a specific reference value with a differential coefficient obtained by frequency differentiating the coefficient distribution of the harmonics calculated by the functional operation section which have harmonic degree equal to or less than several tens degree of the Fourier series, and for controlling the noise elimination circuit by making a decision of the presence or absence of the waveform symmetry with respect to the center value in values input to said noise elimination circuit of the pulse-like noise component from the comparison result.