High speed quantization-level-sampling modem with equalization arrangement
US5528625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1994 |
| Grant date | Jun 18, 1996 |
| Priority date | — |
| Expiry date | Jan 3, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4927
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
The present invention is a quantization-level-sampling (QLS) modem which includes means for separately equalizing each loop of an end-to-end digital telephone system network connection by employing a plurality of transmitter filters and a plurality of receiver filters in such a way that, in the direction of transmission from modem to central office, the voltage samples seen by the coder/decoder stations are equivalent to the network quantization levels transmitted by the modem, and in the direction of transmission from central office to modem, the voltage samples seen by the modem are equivalent to the network quantization levels encoded by the coder/decoder stations. The invention also includes a QLS modem communications system which includes the aforesaid digital telephone system network and a plurality of QLS modems. In preferred embodiments, an adaptation service unit within the telephone system network assists in the determination of the settings of the transmitter and receiver filters.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.