Telecommunications transmission systems
US7079610B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1999 |
| Grant date | Jul 18, 2006 |
| Priority date | — |
| Expiry date | May 11, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03617
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a multi-carrier system employing OFDM, for example DMT, an adaptive channel equalizer is normally used, operating in the frequency domain. The sampling clock is controlled so that the time delay between the transmitter and the receiver is effectively eliminated. If the information used to control the sampling clock is received from the equalized data stream, it will introduce an ambiguity between the operation of the channel equalizer and the mechanism used to control the sampling clock. Operation of the equalizer can mask an increasing time difference, between transmitter and receiver, which the sample clock controller should be tracking. The present invention eliminates the ambiguities in the operation of the equalizer and sample clock controller by preventing the equalizer from accepting time differences which should be corrected by operation of the sample clock controller.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.