Method of and apparatus for generating PCM code sets
US6563878B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 30, 1999 |
| Grant date | May 13, 2003 |
| Priority date | — |
| Expiry date | Jul 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4927
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for generating a PCM code set for encoding data by a PCM encoder in a data transmission system having a digital modem with a PCM encoder, a digital signal transmission path, an analogue signal transmission path with a central office line interface portion, and an analogue modem. The method includes the step of determining a minimum signal level distance between adjacent PCM codes of the PCM code set, the minimum signal level distance enabling discrimination by the analogue modem. Then a line interface attenuation of the central office line interface portion is determined. Finally, the PCM code set on the basis of a power limit computed by adding the line interface attenuation to a central office line interface power limit is generated. The invention further relates to an analogue modem to be operated in such a data transmission system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.