Sampled amplitude read channel employing early-decisions from a trellis sequence detector for sampling value estimation
US6246723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 4, 1998 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | May 4, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L1/0054
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A sampled amplitude read channel is disclosed for disc storage systems that extracts early-decisions from a discrete-time trellis sequence detector to generate estimated target values for use in decision-directed timing recovery, gain control, and adaptive equalization. The trellis sequence detector comprises a metric generator for generating error metrics corresponding to a plurality of states of a state transition diagram, and a plurality of path memories which correspond to the paths of a trellis. The path memories store a plurality of survivor sequences which eventually merge into a most likely sequence at the output of the path memories. To reduce the latency in generating the estimated target samples, the trellis sequence detector outputs an early-decision from an intermediate location within the path memories. The early-decision is then converted into the partial response signaling space of the read signal samples. To improve the accuracy in estimating the target sample values, the accumulated metrics of a predetermined number of states are compared and the early-decision value is selected from the path memory having the smallest error metric. Alternatively, a majority-vote …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.