| 摘要 |
<p>PURPOSE: Systems and methods for improving the audio quality of frequency modulation (FM) receivers are provided to reduce hissing background noise and static. CONSTITUTION: A stop band noise signal is extracted from an L+R signal generated by an FM stereo decoder or an L-R signal generated by the FM stereo decoder. A channel quality measure is calculated based on the stop band noise signal. Noise pulses are detected from the L+R signal (408). The detected noise pulses are removed based on the channel quality measure. [Reference numerals] (402) Applying orthogonal L-R demodulation to a composite baseband signal outputted by an FM demodulator for obtaining an L-R noise signal; (404) Calculating estimated CNR based on the L-R noise signal; (406) Determining whether the estimated CNR is under the predetermined threshold value; (408) Responding to the determination where the estimated CNR is under the threshold value, detecting noise pulse from an L+R signal obtained from the composite baseband signal, eliminating the detected noise pulse by using multiple noise pulse templates</p> |
