Codec supporting PCM modem communications over a universal digital loop carrier
US6151364A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1998 |
| Grant date | Nov 21, 2000 |
| Priority date | — |
| Expiry date | Oct 30, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4927
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
A codec supports PCM modem communications (e.g., V.90, X2, or K56flex protocols) over a universal digital loop carrier (UDLC) having an analog interface to the central office (CO). The codec includes an analog-to-digital converter (ADC) that is synchronized to the CO clock, and an equalizer that has been trained to provide a transfer function to compensate for the distortion introduced by the CO line interface reconstruction filter and connecting circuits, to minimize resampling error. The features allow the codec to output a PCM stream that accurately reproduces the PCM data at the central office, at data rates sufficient to support PCM modem communications, as well as voice and conventional modem communications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.