Circuit for detecting the locked condition of PSK or QAM
US5861773A · kind A · utility
20Cited by
7References
6Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 2, 1997 |
| Grant date | Jan 19, 1999 |
| Priority date | — |
| Expiry date | Dec 2, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S331/02
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method for detecting a locked condition of a demodulator of at least one signal that may have discrete levels defining a constellation of nominal points in a plane. The method includes the steps of defining reference areas about the nominal points, a reference area being separated from another by a band or an angular sector crossing the origin of the constellation plane, and indicating a locked condition if the ratio of points occurring in the reference areas is above the probability for points to occur in the reference area, when the demodulator is wrongly adjusted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.