Constellation detection in a multi-mode QAM communications system
US8374270B2 · kind B2 · utility
1Cited by
7References
12Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 1, 2010 |
| Grant date | Feb 12, 2013 |
| Priority date | — |
| Expiry date | Oct 11, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/42607
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Systems and methods for determining an unknown QPSK or QAM constellation from a set of possible received constellations are described. One method utilizes a histogram of the power of the signal after inter-symbol-interference has been minimized with a modified constant modulus algorithm equalizer. The constellation may be determined before carrier frequency and phase has been fully recovered. An unknown QPSK or QAM constellation may be identified before or after equalization using disclosed methods for analyzing an output power histogram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.