Frequency offset estimator for upstream cable signals
US8755462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 8, 2011 |
| Grant date | Jun 17, 2014 |
| Priority date | — |
| Expiry date | Jan 11, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2027/0095
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a DOCSIS transmission network, it is necessary for an upstream receiver to estimate and correct for errors in the carrier frequency of the transmission based upon observations of a preamble sequence. This task is complicated by the fact that microreflections in the upstream channels cause intersymbol interference, which tends to bias the frequency estimation circuit. An economical, ISI-immune algorithm is provided for estimating the carrier frequency of upstream transmissions. The arrangement improves the reliability of the frequency estimates in the presence of ISI, thereby reducing the overhead and increasing the throughput of the upstream channels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.