Method and apparatus for audio noise reduction of frequency modulation (FM) receiver
US8520779B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 3, 2011 |
| Grant date | Aug 27, 2013 |
| Priority date | — |
| Expiry date | Feb 29, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B1/1669
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A method and an apparatus for audio noise reduction of frequency modulation (FM) receiver are described. After receiving FM signal having pilot tone, pilot carrier sync detector performs pilot carrier synchronization detection of FM signal, FM demodulator demodulates synchronized FM signal, multiplex decoder decodes audio signal of demodulated FM signal for outputting the decoded audio signal, and noise reduction controls multiplex decoder for controlling noise attenuation associated with the decoded audio signal according to RSSI, the method comprising the steps: (a) performing phase error detection for detecting phase error of phase-locked loop (PLL) of pilot carrier sync detector; (b) determining whether noise exists by comparing the phase error with threshold value to determine whether noise exists in the phase error; and (c) performing noise reduction step by outputting noise reduction control signal to noise reduction based on determination in step (b) for reducing noise in the noise existence interval.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.