Multi-level pulse amplitude modulation receiver
US7099400B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 22, 2003 |
| Grant date | Aug 29, 2006 |
| Priority date | — |
| Expiry date | Dec 28, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L25/4917
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
Multiple-level phase amplitude (M-PAM) clock and data recovery circuitry uses information from multiple phase detectors to generate one or more data sampling clocks that are optimized for each of the data slicers. One possible 4-PAM implementation includes 3 data slicers, 3 edge slicers, 3 phase detectors, and a single VCO. The phase detector outputs are combined (e.g., via weighted voting, weighted average, minimum error, and/or minimum variance) to determine an optimized phase estimate for the clock used to sample the data at all three data slicers. Another 4-PAM implementation similarly includes 3 data slicers, 3 edge slicers, 3 phase detectors, and a single VCO. The mid-amplitude edge slicer and phase detector are used in combination with the VCO to generate a central phase while a multiple-tap delay line provides N phase variants before and after the central phase. Information from the non-mid-amplitude edge slicers and phase detectors is used to choose a phase from among the phase variants that best suits the other data slicers. In yet another implementation, a single edge slicer, single phase detector, and single VCO is used to generate a key clock which is used by the edge …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.