Noise cancellor

Abstract

If a mode calculating section ( 52 ) judges that an inputted modulated signal is nearly in a no-sound state, the interpolation width determined by an interpolation width calculating section ( 53 ) is increased, whereas if the mode calculating section ( 52 ) judges that the inputted modulated signal contains a lot of high-frequency components, the interpolation width determined by the interpolation width calculating section ( 53 ) is decreased.

Description

technical field [0001] The present invention relates to a noise canceller for canceling noise contained in an input signal, and more particularly, to a noise canceller included in an FM (Frequency Modulation) receiver device for canceling noise contained in an FM reception signal. Background technique [0002] In a vehicle-mounted FM receiving apparatus, a received FM signal has impulse noise such as ignition noise superimposed thereon, and therefore, in order to eliminate such impulse noise contained in an FM reception signal, a noise canceller is provided. [0003] With a conventional noise canceller, when receiving a composite signal having impulse noise superimposed thereon as shown in FIG. 6A, the impulse noise is detected by passing the composite signal through an HPF (High Pass Filter). When the HPF detects impulse noise, an impulse noise detection signal as shown in FIG. 6B is generated. When the impulse noise detection signal is applied to an integrator, the integr...

AI Technical Summary

Problems solved by technology

However, there is no difference between this method and the method shown in Figs. 6A-6D, because the impulse noise is eliminated by keeping the signal level at the signal level immediately before the impulse noise occurs, thereby causing distortion of the received signal

Images