| 摘要 |
PURPOSE:To facilitate the elimination of a narrow band disturbing wave by using a notch filter for the side of a reference signal of a correlation device. CONSTITUTION:An adaptive filter 5 is provided on the side of a reference signal of a correlation demodulator 6 to deform a P code spectrum for reference in response to the output of a detection means 4. When a disturbing signal is inputted, the detection means 4 detects a disturbing frequency fu to control the adaptive filter 5 so that a notch appears in the frequency of fu-f0. In order to prevent the disturbing wave component from appearing at the output of a band pass filter 17, the component of a range (f) given by equation of fu-f0-Bs<=f<=fu-f0+Bs is required in the spectrum of a reference signal. Then the characteristic of the adaptive filter 5 has a prescribed spectrum. Thus, the distributing wave component in the output of the band pass filter 17 is reduced. |
