Adaptive computation of symbol probabilities in n-ary strings
US5357250A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 1992 |
| Grant date | Oct 18, 1994 |
| Priority date | — |
| Expiry date | Nov 20, 2012 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M7/4006
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus are provided for adaptively and predictively determining probabilities of occurrence for each symbol of a finite alphabet within a symbol string. A plurality of intervals are defined over a portion of the symbol string. As successive new symbols are added to the string, they enter the intervals, and old symbols pass out of the intervals. A probability for each symbol of the alphabet is maintained and updated by the following process. For each new symbol which enters the intervals, it is determined whether the new symbol is a given character of the alphabet, and whether each old symbol leaving each interval is the given character. Accordingly, the number of occurrences of the given character within each interval may change. A probability update value is determined, having a component from each interval determined by whether the number of occurrences of the given character in that interval changed. Preferably the update value is a binary number having a bit position corresponding to each interval. The probability of occurrence of the given symbol is updated using the probability update value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.