Fast and reliable data carrier detection by a cable modem in a cable television plant
US7469414B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2003 |
| Grant date | Dec 23, 2008 |
| Priority date | — |
| Expiry date | Dec 12, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/426
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus, methods, and computer program products for detecting or locating a viable data carrier in a downstream channel by a cable modem. Potential channels for data carriers can be eliminated quickly by going through a “screening” process, i.e., the first constellation diagram match, thereby preventing those potential channels from going through a significantly more time-consuming second constellation match. The determination of whether the signal in the potential channel is modulated according to the first particular modulation scheme is done rapidly and only potential channels containing a signal likely to be modulated according to the second particular modulation scheme are examined for the second determination step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.