Method and apparatus for generating branch metrics and branch indices for convolutional code Viterbi decoders
US5970104A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1997 |
| Grant date | Oct 19, 1999 |
| Priority date | — |
| Expiry date | Mar 19, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M13/6561
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A Viterbi decoder generates a branch metric table from first and second data signals taken at two sample times and provides selected branch metrics to an add/compare/select circuit in response to branch indices from a branch index generator. The branch metrics in the branch metric table are the sixteen combinations of the sum of the first and second parallel data signals at first and second sample times and the inverse of such signals. The branch index generator generates the branch indices in response to a received state from the add/compare/select circuit, convolutional code polynomials and the possible states of a radix-4 trellis. The add/compare/select generates a survivor path decision based on the selected branch metrics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.