Markov processor for context encoding from given characters and for character decoding from given contexts
US4099257A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1976 |
| Grant date | Jul 4, 1978 |
| Priority date | — |
| Expiry date | Sep 2, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/42
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In an apparatus for generating variable length codewords c(a.sub.i) and c(a.sub.j) responsive to corresponding fixed length codewords b(a.sub.i) and b(a.sub.j), where a.sub.i and a.sub.j are source alphabet characters, a.sub.i .epsilon. A.sub.1 and a.sub.j .epsilon. A.sub.2, ambiguity arises whenever any fixed length character to be encoded can instantaneously represent source characters a.sub.i and a.sub.j drawn from two or more dissimilar alphabets i.e. A.sub.1 or A.sub.2. This is resolved by the inclusion of a Markov processor in combination with the apparatus. The processor establishes the point in the sequence when transitions occur between fixed length characters in one alphabet to fixed length characters in another alphabet by the message context. The processor includes a map of state and transition paths. This map models certain statistical regularities of runs of fixed code elements and the relative likelihood that an ambiguous fixed code character appearing in a first run belongs to a given alphabet. The processor, starting from an arbitrary initial position, tracks any given run of fixed code characters applied to the encoder in terms of a succession of states and paths.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.