Systems, methods and computer program products for identifying digital impairments in modems based on clusters and/or skips in pulse code modulation signal levels
US6816545B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 29, 1999 |
| Grant date | Nov 9, 2004 |
| Priority date | — |
| Expiry date | Oct 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4927
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Digital impairments in a set of Pulse Code Modulation (PCM) signal levels that are received at a client modem from a server modem are identified by compressing the set of PCM signal levels into a signature. Digital impairments are determined based on the signature. In a preferred embodiment, the PCM signal levels are compressed into a signature by identifying clusters and/or skips in the set of PCM signal levels. In particular, when transmitting PCM signal levels from a server modem to a client modem over a connection that is subject to digital impairments such as Robbed Bit Signaling (RBS) and/or PAD digital impairments and quantization, some adjacent PCM signal levels may become identical or very close to one another. Moreover, other adjacent signal levels may have a difference that is at least approximately twice the difference of other levels. The former phenomenon is referred to as a “cluster” and the latter phenomenon is referred to as a “skip”. By identifying clusters and/or skips in the set of PCM signals that are received at the client modem from the server modem, a signature of the network connection may be obtained. Digital impairments including R…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.