Trace-ahead method and apparatus for determining survivor paths in a Viterbi detector
US7669110B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2005 |
| Grant date | Feb 23, 2010 |
| Priority date | — |
| Expiry date | Mar 14, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/4161
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Methods and apparatus are provided for determining survivor paths in a Viterbi detector, using a trace-ahead algorithm. A trellis memory is maintained having a depth L that stores L trellis stages, each of the L stages having a plurality, N, of trellis states; and a status memory is maintained for each of the N states of the trellis, wherein each entry in the status memory identifies a least recent trellis state stored in the trellis memory of a survivor path that begins at a given state on a side of the trellis associated with most recent states. A bit sequence of one or more of the survivor paths in the trellis is determined in an order that the bits are received by examining least and most recent trellis stages of the trellis and the status memory. One or fork memories maintain an indicator of whether a given fork is active; a list of active forks; a trellis position of active forks in the trellis; and a fork type of one or more forks in the trellis.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.