Receiving apparatus
US6744828B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 23, 2000 |
| Grant date | Jun 1, 2004 |
| Priority date | — |
| Expiry date | May 23, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L27/2676
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
An intermediate frequency signal SIF is demodulated and the noise component contained in a null portion (no-signal portion) is detected as the noise component contained in a signal of the sub-carrier frequencies. The frequency f0 of a reference frequency signal LO of a local oscillator 24 is feedback-controlled in accordance with the noise component thus detected. Further, the frequency f0 of the reference frequency signal LO is feedback-controlled in accordance with an error rate detected by an error correction section 23. Thus, the sub-carriers within the intermediate frequency signal SIF subjected to the frequency conversion by a mixer 16 based on the reference frequency signal LO thus feedback-controlled is separated from the noise component on the frequency axis. The intermediate frequency signal SIF is subjected to the Fourier transformation by a digital mixer/FFT calculation section 21, so that the noise component can be suppressed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.