Adaptive equalization and interpolated timing recovery in a sampled amplitude read channel for magnetic recording
US6819514B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 30, 1996 |
| Grant date | Nov 16, 2004 |
| Priority date | — |
| Expiry date | Mar 14, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B20/1258
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A sampled amplitude read channel for magnetic disk recording which asynchronously samples the analog read signal, adaptively equalizes the resulting discrete time sample values according to a target partial response, extracts synchronous sample values through interpolated timing recovery, and detects digital data from the synchronous sample values using a Viterbi sequence detector is disclosed. To minimize interference from the timing and gain control loops, the phase and magnitude response of the adaptive equalizer filter are constrained at a predetermined frequency using an optimal orthogonal projection operation as a modification to a least mean square (LMS) adaptation algorithm. Further, with interpolated timing recovery, the equalizer filter and its associated latency are removed from the timing recovery loop, thereby allowing a higher order discrete time filter and a lower order analog filter.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.