Method and apparatus for adjustment of the sampling phase in a PCM modem system using a dual-phase probing signal
US6456651B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 4, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Feb 4, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L7/0029
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
In a PCM modem system, a method and apparatus for optimizing the fractional sampling phase offset in the upstream direction to maximize the upstream data rate utilizes a probing signal from the analog modem generated during startup and having at least two distinct phases of a pure tone, with the probing signal being detected at the digital modem where an optimum sampling phase value is calculated. From this calculated value, a signal representing the appropriate amount to delay the input data stream is transmitted back to the analog modem for adjustment of the fractional sampling phase so that the fractional sampling phase offset at the central office quantizer is optimized.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.