Method of adaptive equalization for high-speed NRZ and multi-level signal data communications
US7426235B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 2004 |
| Grant date | Sep 16, 2008 |
| Priority date | — |
| Expiry date | Nov 7, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2025/03802
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Circuitry for equalizing a high data rate serial data stream that receives low frequency and high frequency test tones, accurately measures an amount of attenuation experienced by the high frequency test tone in relation to the low frequency test tone, and accordingly, produces equalization data that results in a corresponding amount of equalization or pre-emphasis being added to an outgoing signal. More specifically, however, the present invention includes both open loop and closed loop systems for equalizing or adding pre-emphasis to a signal with attenuation. In the open loop transceiver system, a presumption is made that an amount of attenuation in both the outgoing and ingoing directions are equal. In the closed loop transceiver system, a receiver determines an amount of equalization and produces the equalization data to a remote transceiver.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.