VSB/QAM receiver and method
US6842488B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Feb 28, 2001 |
| Grant date | Jan 11, 2005 |
| Priority date | — |
| Expiry date | Feb 17, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0087
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A vestigial sideband/quadrature amplitude modulation (VSB/QAM) receiver, which receives both VSB and QAM signals and restores a carrier wave with a restored symbol clock after restoring a symbol timing in a front portion of a carrier wave restoration unit. The receiver has an analog-digital converter for A/D converting in accordance with a frequency higher than a symbol frequency of a received signal; an interpolator for calculating a signal value on the original symbol location after a signal from the A/D converter is applied; the carrier wave restoration unit for restoring a carrier wave by selectively using an automatic frequency control (AFC) and a digital frequency phase locked loop (DFPLL) in accordance with a VSB/QAM mode after a signal from the interpolator is applied; a timing processor for receiving a signal from the carrier wave restoration unit, detecting a timing error after changing a symbol input time in accordance with a VSB/QAM mode, controlling the interpolator based on the detected timing error, and generating a restored clock; and a VSB sorter for extracting a VSB receiving symbol.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.