US 2001/0044289 A1 · Multipath noise reducer, audio output circuit, and FM receiver

Abstract

A multipath noise reducer detects and removes the individual noise spikes occurring in an interval of multipath noise, thereby reducing the multipath noise with relatively little distortion of the output signal. The threshold signal used to detect multipath noise is varied depending on reception conditions. The gate pulses indicating the presence of multipath noise spikes are preferably expanded by variable amounts, depending on both reception conditions and the signal level. Multipath noise spikes are preferably replaced by a smoothed signal. These provisions further reduce perceived distortion of the audio output signal.

Claims18

Dependent claims

A multipath noise reducer for reducing multipath noise in an input signal, comprising:

a signal state determiner determining a state of said input signal, thereby generating state information;
a threshold generator coupled to said signal state determiner, generating a threshold value responsive to said state information;
a high-frequency signal extractor detecting high-frequency components of said input signal, thereby obtaining a high-frequency signal;
a comparator unit coupled to said threshold generator and said high-frequency signal extractor, comparing said high-frequency signal with said threshold value, thereby generating a multipath noise detection signal;
and
a correction unit coupled to said comparator unit, modifying said input signal responsive to said multipath noise detection signal and said state information, thereby generating a corrected output signal.

3 more elements

Dependencies are inferred from the claim text.

Multipath noise reducer, audio output circuit, and FM receiver

Life of this patent

Multipath noise reducer, audio output circuit, and FM receiver

Life of this patent

Abstract

Claims18