Direct digital synthesis in a QAM demodulator
US6249179A · kind A · utility
15Cited by
2References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 17, 2000 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Apr 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0081
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A quadrature amplitude modulation (QAM) type demodulator having a pair of direct digital synthesizer (DDS) circuits. The first DDS circuit is located in a baseband conversion circuit before a receive filter and digitally tunes the signal within the receive filter bandwidth. The second DDS circuit is within a carrier recovery circuit located after the receive filter and serves to fine tune the signal phase.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.